Scientific Program of 38th World Congress Of Endourology Program Book

MP01-01 Seasonal and COVID Pandemic‐Related Variations in Patients' Self‐Reported Adherence to Nutrition Recommendations for Stone Prevention Suggest Temporal Increases in Stone Recurrence Risk

KL Penniston, K Schobert, RJ Medenwald

University of Wisconsin School of Medicine and Public Health

Introduction & Objective: Nutrition therapy for stone prevention is indicated if risks are nutrition‐related. Common dietary recommendations (DRs) include higher fluid intake, lower salt intake, lower dietary acid load (e.g., more fruits/vegetables, F/V), and normal calcium intake (neither excessive nor insufficient). Adherence is challenging to assess and optimally includes multiple measures including patient‐reported outcomes. We assessed adherence to individualized, targeted DRs issued in our multidisciplinary stone prevention clinic.

Methods: From 1/2020‐1/2021 we invited patients to complete a questionnaire approximately 1 month after their appointment. We asked patients to estimate the number of days within the last week they followed the most common DRs and, in a separate question, days they followed all DRs. Questionnaires were sent by mail with postage‐paid envelopes for return. This was a quality improvement project; patients were thus offered to respond anonymously.

Results: Respondents (n = 132) represented 29% of patients who were sent questionnaires and were 50% female (61 ± 13 y). Of those providing clinical details, 77% were recurrent stone formers and 46% were on stone medication(s). There were no differences in adherence for men vs. women, recurrent vs. one‐time stone formers, nor for those on stone‐related medications vs. not. Overall, adherence to eating more F/V was lower (4.7 vs. nearly 5.5 d/week for all other DRs, P < 0.004). We separated responses by their receipt: summer/fall (April to mid‐November) and winter/spring (mid‐November to April), and by pre‐ vs. post‐COVID (before/after March 2020). F/V intake was significantly lower during winter/spring than summer/fall (4.4 vs. 5.5 d/week, P = 0.009). For the pre‐post COVID pandemic comparison, patients reported lower adherence to all DRs after the start of the pandemic (5.0 vs. 5.9 d/week, P = 0.009 for difference from before).

Conclusions: Overall, adherence to eating more F/V was significantly lower than for other DRs and was lower yet during winter/spring. The COVID pandemic did not affect F/V intake specifically but did reduce adherence to all DRs. F/V are important in stone prevention because they provide bicarbonate precursors that increase urine citrate and pH. F/V also provide other stone inhibitors, including phytate, which in urine inhibits calcium stone formation, and prebiotics, some of which selectively enhance oxalate‐degrading gut bacteria. Moreover, F/V intake can account for up to 30% of urine output and thus may help to meet fluid recommendations. Barriers to F/V intake, which may include seasonal variations in cost and availability, should be addressed.

MP01-02 Withdrawn

MP01-03 Percutaneous nephrostomy in Ureteropelvic junction obstruction with poorly functioning kidney: Is it still pertinent in adults

A Srivastava, S Kakoti, Z Tamboli, SK Sureka, UP Singh

Sanjay Gandhi Post Graduate institute of medical sciences. Lucknow

Introduction & Objective: To determine the pertinence of percutaneous nephrostomy (PCN) drainage in adult patients of primary uretero‐pelvic junction (UPJ) obstruction with poorly functioning kidneys (PFK; < 20% split renal function).

Methods: Clinical records of all patients with primary UPJ obstruction with PFK who underwent PCN drainage in our institute between February 2015 and January 2020 were retrospectively reviewed. The patients were divided into four groups according to their split renal function (SRF) obtained from Tc‐99m‐ethylenedicysteine (EC) diuretic renogram. Group I consisted of all patients having SRF ≤5%, Group II with SRF 6‐10%, Group III with SRF 11‐15%, and finally group IV with SRF 16‐20%. Those patients in whom SRF was improved by >10% and had daily PCN output >400 ml, underwent pyeloplasty and the rest underwent nephrectomy.

Results: 72 patients were studied, out of which 5 were in group I, 20 in group II and III each, and 27 in group IV. The mean age of presentation was 34.4 ± 14 years. The SRF improvement of >10% was seen in 55 patients (76.4%) after PCN drainage (p < 0.05). Pyeloplasty was done in 40 patients (55.6%) and nephrectomy was done in 32 patients (44.4%).

Conclusions: In conclusion, we recommend the use of Tc‐99m EC scan for estimation of SRF during an initial presentation in every patient followed by reconstructive surgery if SRF is above 15% and nephrectomy if it is below 5%. The trial of PCN is pertinent if SRF is between 6% to 15%.

MP01-04 Kidney stone disease prevalence from administrative coding compared to self‐report: a report from the All of Us Research Program

CM Forbes, N Nimmagadda, NL Kavoussi, NL Miller, R Hsi

Vanderbilt University Medical Center, Department of Urology

Introduction & Objective: Kidney stone prevalence estimates determined by administrative claims data and by self‐report differ due to their methodologic differences. To better characterize these differences and to identify contributing demographic and socioeconomic factors that influence how kidney stone diagnoses are ascertained, we sought to compare rates of patient‐reported diagnoses to administrative claims using a common dataset derived from recruitment of diverse populations in the U.S.

Methods: From the All of Us Research Program data, we identified adult participants with and without a patient‐reported history of kidney stones at enrollment in 2016‐2018, and with and without administrative claims (1980‐2017) for kidney stone diagnoses. Among 223,921 participants including 52% persons from racial minorities, there were 21,712 participants who had both patient‐reported medical history and medical claims data available for analysis. We compared differences in age, sex, race, education, employment status and healthcare access among patients with self‐reported kidney stone history without medical claims to those with claims‐based diagnoses.

Results: The claims‐based prevalence of kidney stones was 5.7% (n = 1231) and by self‐report it was 8.6% (n = 1877). Among participants with either kidney stone‐specific claims or self‐reported history (n = 2235), there were 45% (n = 1004) who had self‐reported history only. This indicates that that almost half of the participants with kidney stones did not have a prior kidney‐stone specific medical claim. Compared to participants with any kidney stone‐specific claim, participants with only self‐reported history were younger (62 vs 63, p < 0.001) (Table 1). No differences were observed in sex, race, education, employment status, and ability to afford healthcare between groups.

Conclusions: Kidney stone prevalence by self‐report is higher than claims‐based prevalence in this national research program. According to our findings, self‐managed stone disease without clinical care is common and occurs in almost half of patients with kidney stones. No notable differences in demographic and socioeconomic factors were observed among kidney stone patients with and without clinical care.

MP01-05 A Delphi Process Consensus Statement on Urinary Stone Treatment During COVID‐19: A World Endourological Society TOWER Research Initiative

R Smith, T Tailly, BH Chew, N Bhojani, KB Scotland

Institute of Urology, University College London Hospitals NHS Foundation Trust

Introduction & Objective: COVID‐19 continues to have a profound effect on urolithiasis management with varying recommendations for prioritization across different healthcare systems. We used the Delphi method to obtain international consensus recommendations for managing urolithiasis during the pandemic.

Methods: 53 key opinion leaders from 36 countries within the Endourological Society contributed to a three‐round Delphi process addressing the general organisation, inpatient and outpatient management and follow‐up care of urolithiasis patients to determine best practices for suspension and resumption of care.

Results: Consensus was achieved in 64/84 (76%) questions allowing the following recommendations to be made for the management of Urolithiasis during the pandemic.

1 Consultations should ideally be delivered via telephone or video conferencing, prioritizing patients with Infection, acute kidney injury, pain including acute ureteric colic and visible haematuria.

2 The Surgical focus should be to reduce the risk of complications even if it means a planned secondary procedure

3 Surgery should be reserved for high risk patients (solitary kidney, bilateral ureteral obstruction), infected patients, patients at risk of acute kidney injury or those with uncontrollable pain.

4 Primary definitive treatment of obstructing or symptomatic stones (both renal and ureteral) is preferred over temporizing drainage.

5 ESWL should be continued for ureteric stones but not for asymptomatic renal stones

6 Spinal Anaesthesia was recommended for distal Ureteric Stones under 10mm

7 For symptomatic renal stones, Flexible ureterorenoscopy (FURS) was recommended for 11‐20mm and PCNL/ECIRS for stones >20mm

8 Following Uncomplicated URS/FURS “Stent‐on‐a‐string” was recommended for stones 5‐20mm at all positions, with “stent and cystoscopic removal” for stones >20mm at all locations

9 Following Complicated URS/FURS stent and cystoscopic removal was recommended for all stone sizes and locations.

10 Following PCNL, some form of drainage was recommended for all complicated PCNLs and for uncomplicated PCNL for stones >11mm.

11 Surgical education should be maintained for trainees involved in the patients care.

12 Follow up imaging should continue for conservatively and actively treated ureteric colic and for patients with symptomatic renal stones

13 Imaging follow up can be deferred for asymptomatic prior stone formers including those with an established renal stone.

Conclusions: These recommendations can be applied currently during the ongoing Covid‐19 pandemic and be used as a framework for practice during a future catastrophic event that impacts the practice of renal and ureteric stone surgery.

MP01-06 Prospective non‐randomized comparison of transperitoneal transvesical versus extravesical laparoscopic supratrigonal vesico‐vaginal fistula repair: A single centre experience

V Singh, RJ Sinha, G Singh

Dept of urology, King George Medical University

Introduction & Objective: To compare the technique of transperitoneal transvesical versus extravesical laparoscopic repair of supratrigonal vesico‐vaginal fistula (VVF) and to assess the outcome of the two techniques.

Methods: Between January 2010 and September 2019, 22 patients with supratrigonal VVF underwent repair by laparoscopic technique. Single supratrigonal fistula was present in all these patients. Obstetric fistula was in present in 14 patients and gynaecologic fistula was present in 8. Mean fistula size was 1.5 cm (range 1 ‐ 3 cm). Transperitoneal transvesical laparoscopic repair (TTLR) was performed in 12 patients and transperitoneal extravesical laparoscopic repair (TELR) in 10 patients. The median follow‐up of these patients is 22 months in TTLR group and 24 months in TELR group.

Results: Mean operative time was 160.89 ± 12 minutes in TTLR versus 145.78 ± 0.8 minutes in TELR group (p < 0.001). Mean blood loss was 80.03 ± 0.7 ml in TTLR versus 60 ± 0.6 ml in TELR group (p < 0.001). Mean tramadol requirement on the first postoperative day was 200.06 ± 15 mg in TTLR versus 175.08 ± 12 mg in TELR group (p < 0.001). Mean hospital stay was 6.63 ± 0.74 days in TTLR versus 5.56 ± 0.67 in TELR group. None of the patients required open conversion. One patient in TTLR group had leakage on 12th day of fistula repair which was managed after 3 months by trans‐abdominal repair with omental flap interposition. The success rate of fistula repair was 91.6% in TTLR versus 100% in TELR group.

Conclusions: TTLR is associated with significantly long operative time, more blood loss, more analgesic requirement on first postoperative day in comparison to TELR. However the there was no difference between two groups with respect to overall success of fistula repair and length of hospital stay.

MP01-07 Identifying patients who will benefit from extended pelvic lymph‐node dissection during radical prostatectomy: a novel nomogram based on target biopsy only

E Checcucci, C Fiori, I Stura, D Amparore, S De Cillis, A Pecoraro, P Alessio, A Piana, F Piramide, G Volpi, P Verri, S Granato, B Carbonaro, D Zamengo, A De Pascale, D Gned, M Manfredi, G Migliaretti, F Porpiglia

Department of Urology, AOU San Luigi Gonzaga ‐ University of Turin

Introduction & Objective: Nowadays, the role of synchronous pelvic extended lymphadenectomy (ePLND) during prostatectomy for prostate cancer still remains discussed. Various different tools aiming to identify patients who will benefit from ePLND are available such as mp‐MRI. However, also other instruments such as nomograms, can help the surgeon during the decision‐making process in case of positive target biopsy (TB) alone. The aim of our study was to develop a novel model based on mp‐MRI findings and TB alone in order to predict the risk of Lymph Node Invasion (LNI).

Methods: We retrospectively extracted from our prospectively maintained database patients with preoperative positive mp‐MRI and TB who underwent robotic prostatectomy with ePLND from April 2014 to March 2020. A logistic regression model was performed to evaluate the impact of pre‐ and intra‐operative factors on the risk of LNI. The results are shown in terms of Odds Ratio (OR) with a 95% Confidence Interval (95%CI). Model discrimination was assessed using an area under curve (AUC), the receiver operating characteristic (ROC) curve. A nomogram to predict the risk of LNI based on the logistic model was generated. The proposed model cut‐off was chosen maximizing both sensitivity and Youden score.

Results: Overall, 461 patients were included in our study; among them 52 (11.27%) had LNI. At logistic regression DRE, MRI findings (organ confined vs ECE, vs SVI), PI‐RADS, seminal vesicle invasion, PSA and worst GS at I and II target lesions were significant predictors of LNI. At multivariable model, DRE (OR 0.56; C.I.: 0.30‐1.05) and SVI (OR: 0.42; C.I.: 0.19‐0.93) were the most significant variables, followed by PSA (OR: 0.30; C.I.: 0.21‐0.73) and worst GS at I (OR: 0.37; C.I.: 0.17‐0.82) and II target lesion (OR: 0.33; C.I.: 0.14‐0.76). The AUC was 0.74 [0.67‐0.81] 95% CI. This predictive model was subsequently transformed into a visual nomogram, as shown in Figure 1. The cut‐off to discriminate LNI risk was set with a Youden index of 60 points, corresponding to a LIN risk of 7%.

Conclusions: The results of our study demonstrate that ePLND can be avoided in patients with positive TB only, being the risk of LNI below 7%, in order to spare approximately 59.1% of ePLNDs at the cost of missing only 4.7% positive LNs.

MP01-08 Clinical significance of markers of acute renal injury in predicting adverse outcomes in patients with coronavirus infection

V Pavlov, I Kabirov, A Alekseev, A Tarasenko, R Abdrakhimov, AO Papoyan

Bashkir State Medical University

Introduction & Objective: Coronavirus Disease 2019 (COVID‐19) is a newly emerging respiratory infection with frequent acute kidney injury (AKI). However, dynamic changes in kidney function and its relationship to predicting COVID‐19 outcomes are not sufficiently defined to apply preventive measures in patient management strategies. , especially in patients with concomitant diseases or undergoing surgery.

Methods: This single‐center retrospective cohort study analyzed the clinical characteristics, medical history, laboratory and instrumental studies and treatment data of 160 patients with COVID‐19, among whom at the time of hospitalization there were no clinical signs of AKI according to the criteria, there were 40 people who analyzed the data of the marker panel. AKI: urine NGAL, serum CisC, urine IL‐18, the sensitivity, specificity and threshold values of which were determined from the ROC analysis of 236 patients with initially diagnosed AKI during hospitalization. Renal function was assessed using the calculated GFR equation (CKD‐EPI 2009) based on serum creatinine levels.

Results: AKI at hospitalization was detected in 16 patients, Distribution by stages: 8.13%, 12.6% and 24.5% according to the KDIGO criteria. The ROC analysis determined the threshold value of the Marker Panel in patients with AKI at hospitalization, which was 156.87 ng / ml NGAL, 79.42 ± 13.69 for IL‐18, and 175.0 ± 16.63 for SCysC. The sensitivity of the method was 80% and the specificity was 73.7%. Based on the panel of markers, a subclinical form of AKI was identified, the outcomes of which were assessed within 3 months. In 14 patients of this group, a decrease in the GFR level was recorded within 30 days after hospitalization, associated with a lethal outcome. Mortality within 30 days from common causes was 8.3%

Conclusions: The increased risk of death from all causes was associated with increased levels of the AKI and Scr panel markers in the control group. Dynamic changes in the three markers of kidney function have been associated with varying degrees of severity and poor prognosis in COVID‐19 patients. The AKI marker panel has demonstrated high potential for predicting adverse outcomes in COVID‐19 patients for severity stratification and patient strategy.

MP01-09 The impact of the COVID‐19 pandemic on the presentation and management of renal colic patients

S Mukherjee, H Kadhim, I Sahibzada, D Feflea, L Goldsmith, C Popanes, A Raza

London North West University Healthcare NHS Trust

Introduction & Objective: Renal colic is one of the common urological emergencies. As the COVID‐19 pandemic significantly impacted the UK healthcare system, there were some changes in the presentation and management of renal colic patients during the pandemic compared to the pre‐pandemic period. We compared the presentation and management of renal colic patients between the pandemic and pre‐pandemic period.

Methods: Retrospective data analysis from electronic patient records was conducted for all adult patients presenting to our A&E department with a radiological diagnosis of renal colic between March‐May 2020 (the first peak of the pandemic) comparing similar data collected for the period March‐May 2019.

Results: During the pandemic, the total number of patients attending A&E with a clinical diagnosis of renal colic and CT scan confirming stone in ureter/PUJ reduced by 17% compared to the same period in 2019 (170 vs 204).

Relatively younger patients attended A&E during the pandemic compared to the pre‐pandemic period (median age in years [IQR] ‐ 43.5 [34, 52] vs 39 [31, 50], p = 0.016) and there were significantly more patients with PUJ stones in 2019 than in 2020 (18 vs 1, p = 0.0003). However, there was no difference in other patient characteristics or stone characteristics.

Also, there was no difference in the proportion of patients managed conservatively between the pandemic and pre‐pandemic period (79% vs 78%, p = 0.83). However, between 2020 and 2019, there was a significant reduction in hospitalization (18 (10.6%) vs 49 (24%), p = 0.0008), JJ stent insertion (6 (3.5%) vs 24 (11.7%), p = 0.004) and ureteroscopy as initial definitive treatment (4 (2.4%) vs 29 (14.2%), p = 0.0001) along with a significant increase in primary ESWL (25 (14.7%) vs 9 (4.4%), p = 0.0006).

Conclusions: The COVID‐19 pandemic resulted in a considerable drop in A&E attendance of renal colic patients. The reduction was more noticeable in older patients compared to the younger patients. In addition, there was change in standard management strategy from stent insertion followed by a second admission for ureteroscopy towards urgent primary ESWL.

MP01-10 “Pseudo‐renal colic” – a neglected common entity with significant impact on health service providers' resources during both pre‐ and peri ‐ COVID‐19 pandemic

S Mukherjee

London North West University Healthcare NHS Trust

Introduction & Objective: Renal colic is a common cause of A&E presentation. A significant proportion of patients presenting with renal colic go onto have entirely normal or pathology free CT scans (“pseudo‐renal colic”). Many patients therefore undergo unnecessary radiation exposure from imaging as well as require significant health service providers' resources. We compared the number of renal colic presentations both pre and peri pandemic period.

Methods: Retrospective data collection was conducted on all CT KUB scans performed in A&E following a clinical diagnosis of renal colic. Data collection, analysis and comparison were performed over two periods ‐ pandemic period of March‐May 2020 (first peak of COVID‐19) and pre‐pandemic period of March‐May 2019.

Results: In 2019 (pre‐pandemic period), 609 patients attending A&E with a clinical diagnosis of renal colic underwent low dose CT KUB. 204 (34%) patients had an index stone in the ureter/PUJ, 141 (23%) had non‐stone related pathology (urological and non‐urological) and 264 (43%) had pseudo‐renal colic.

In 2020 (pandemic period), attendances to A&E with a clinical diagnosis of renal colic reduced to 384. During the pandemic, there was significant increase in the proportion of patients with positive CT scans showing a stone in the ureter/PUJ (44% (170/384) vs 34%, p = 0.0006) and a drop in pseudo‐renal colic patients (34% (130/384) vs 43%, p = 0.0032) compared to the pre‐pandemic period. The proportion of patients with non‐stone related pathology (urological and non‐urological) remained relatively stable at 22%.

Conclusions: Pseudo‐renal colic comprised around 40% of renal colic patients during both the pandemic and non‐pandemic period leading to unnecessary radiation exposure and wastage of precious resources. Patients with pseudo‐renal colic possibly experience less pain than genuine ureteric colic and a significant proportion stayed at home during the pandemic. Clinical assessment with the use of the validated Stone Score as well as markers such as WC, CRP and renal function before ordering a CT KUB in suspected renal colic patients may help reduce the number of unnecessary CT scans in the future as well as minimize the drain on health service providers' resources during and after the pandemic.

MP01-11 Assessment of Emergency Department Urolithiasis Presentations During the COVID‐19 Pandemic

DK Agarwal, T Large, M Assmus, ME Rivera

Indiana University Department of Urology

Introduction & Objective: During the unprecedented COVID‐19 pandemic, there have been major changes in healthcare delivery, patients seeking care and access to care. We sought to determine if there were differences in Emergency Department (ED) presentations for urolithiasis and their triage from the ED.

Methods: We assessed the all ED presentations and those for urolithiasis (defined as codes N20.0 and N20.1) from January 2019 through December 2020 at four hospitals (one primary, two secondary and one tertiary/quaternary care) in a single hospital network in the Indianapolis metro area. We also assessed the patient's disposition, either discharged from the ED or admitted to the hospital.

Results: There were 109,656 total ED presentations in 2019 and 1369 ED presentations for urolithiasis (12.5%). In 2020, there were 94143 total ED presentations with 1212 for urolithiasis (12.9%). There was no significant difference between total stone presentation between the 2019 and 2020. In 2020, there were significant increases in the rate of stone presentations in May (1.39% vs 0.010%, p = 0.02) and August (1.64% vs 1.13%, p = 0.0035). There was a significant decrease in the rate of stone presentation in December 2020 compared to December 2019 (0.91% vs 1.34%, p = 0.0096). Figure 1 demonstrates the monthly ED Visits for urolithiasis compared between 2019 and 2020, with the monthly COVID‐19 cases in Indiana. There was a decline in total visits 71.5% of visits were dismissed from the ED in 2019 compared to 70.2% in 2020. There were no differences in the rates of ED discharge or hospital admission on a monthly basis between 2019 and 2020.

Conclusions: Within a hospital system in the Indianapolis metropolitan area, there does not appear to be a change in ED stone presentations or disposition patterns between 2019 and 2020 despite the COVID‐19 pandemic.

MP01-12 Are patients' fears of catching COVID‐19 during an emergency hospital admission with an acute urological problem justified? – A UK epicentre experience

O Gbolahan, V Bonatsos, A Raza

London North West University Healthcare NHS Trust

Introduction & Objective: During the first wave of COVID‐19 patients' anxieties around contracting the virus during an emergency hospital admission were high. Our aim was to establish the risk of catching COVID‐19 as a urology emergency inpatient in our Trust and to assess patients fears and attitudes towards seeking medical help for their acute urological problems.

Methods: A single centre retrospective audit of all urological emergency admissions was made over a 10‐week period (mid‐ March – end of May) in 2019 and compared to (mid‐March – end of May) 2020 during the COVID‐19 pandemic. The number of patients who developed new COVID‐19 symptoms whilst an in‐ patient or had positive swabs within 28 days of discharge was obtained. We performed a post discharge telephone survey of patients based on a COVID‐19 fear questionnaire (FC19‐HVQ) adapted from the validated Fear of COVID‐19 scale.

Results: Compared to 2019 (n = 187), 2020 (n = 122) there was a 35% reduction in the number of patients presenting acutely to our department. 43 of the 122 (35%) patients were swabbed on admission due to possible symptoms of COVID‐19. One patient was found to be COVID‐19 positive. 5 patients had further swabs during their admission; one patient who was negative on admission became positive whilst an inpatient. Accordingly, the overall in‐hospital infection rate with COVID‐19 was 0.82% (1 patient) during or within 28 days of discharge. There was no mortality (0%) related to COVID ‐19.

The majority of patients were afraid to visit A&E or the hospital during the COVID‐19 pandemic crisis. Fewer patients were afraid to visit their local Family Doctor (GP). 28% (n = 14) of responders ignored their symptoms during the pandemic.

Patients were reluctant to seek medical input during COVID‐19 by trying to treat themselves at home with 64% (n = 32) of them stating that they attempted to do so. There was also a degree of intentional delay to visit A&E and the hospital with 56% (n = 28) of our patients admitting to having delayed their attendance.

Conclusions: The risk of contracting COVID 19 whilst a urology in patient in a COVID‐ 19 epicentre was very low (0.82%) with no COVID‐19 related mortality. Our data supports the message that patients with urological emergencies should be educated and encouraged to attend hospital, rather than staying at home, during future surges in the current pandemic. This is to prevent further non COVID‐19 related harm from delayed presentations, undiagnosed pathologies and self‐ treatment approaches.

MP01-13 The effect of the COVID‐19 pandemic on management of urological emergencies including risk of contracting COVID‐19 – a UK epicentre experience

O Gbolahan, V Bonatsos, A Raza

London North West University Healthcare NHS Trust

Introduction & Objective: During the first wave of COVID‐19 we saw a reduction in urgent urological admissions. Concurrently, we had to adapt and change our standard management of urological emergency admissions. We wished to evaluate the impact of COVID‐19 on urological emergencies in a UK COVID‐19 epicentre.

Methods: Retrospective audit of all urological emergencies over a 10‐week period (mid‐March – end of May) in 2019 was compared to the same period during COVID‐19.

Results: From 2019 to 2020 we saw a reduction of 35% (187 [2019] and 122 [2020]) in urological emergency admissions. The average inpatient stay was 1.76 days (range 0‐24 days) in 2020 from 2.65 days (range 0‐38 days) in 2019. The largest reduction in presentation was seen in renal colic 43% (58 [2019] and 33 [2020]) followed by visible haematuria 39% (37 [2019] and 23 [2020]). There was a decrease in surgical management of urological emergencies during COVID‐19. Scrotal exploration for testicular pain went from 57% (21 of 37) 2019 to 39% (12 of 31) during COVID‐19. Stenting for colic and confirmed ureteric stones decreased from (20 of 25) 80% in 2019 to 11% (2 of 18) in 2020. “Hot” ESWL rates for ureteric stones increased from no patients [2019] to 61% (11 of 18) in 2020. In 2019, 12% (6 of 49) of emergency procedures were performed by Consultants however this increased to 48% (11 of 23) in 2020 due to redeployment of urological registrars. The overall in‐hospital COVID‐19 infection rate was only 0.82% during or within 28 days of discharge with no COVID‐19 related mortality (0%).

Conclusions: Inpatient infection rate from COVID‐19 was very low and there was no related mortality therefore patients should not fear hospital attendance or admission. Longer term follow‐up of patients managed conservatively rather than surgically is necessary to ensure no long‐term harm has been caused by a change in standard surgical management of urological emergencies.

MP01-14 Quality of Life of Urolithiasis Patients During the COVID‐19 Pandemic: A Wisconsin Stone Quality of Life (WISQOL) Research Consortium Cross‐Sectional Study

VK Wong, BH Chew, KL Penniston, VG Bird, NM Streeper, SY Nakada, N Bhojani

University of Montreal Hospital Center (CHUM)

Introduction & Objective: The COVID‐19 pandemic is an unprecedented global event that has caused significant fear and anxiety across all populations. To date, there have been no studies on how major health crises have affected the stone‐related quality‐of‐life (QOL) of patients with urolithiasis. In this study, we investigated whether the fear of COVID‐19 affects the QOL of patients with kidney stones during the COVID‐19 pandemic using the Fear of COVID‐19 Scale (FCV‐19S) and the Wisconsin Stone Quality of Life (WISQOL) questionnaires.

Methods: Patient‐reported FCV‐19S and WISQOL data for this multi‐institutional prospective cross‐sectional study were obtained from five sites within the North American Stone Quality of Life Research Consortium. Data collection occurred between the months of April‐October 2020 during the COVID‐19 pandemic where many procedures (radiological or surgical) and visits were either delayed or cancelled. The scores generated from patient‐reported responses were correlated by the Pearson Product‐Moment Correlation. The questionnaire scores were then further sub‐analyzed dependent on categorical responses related to procedural delays or care and were analyzed via the Student's T‐test. A single factor analysis of variance (ANOVA) was performed to analyze varying QOL scores across the FCV‐19S quartiles.

Results: 400 respondents participated in this study. Within the cohort, mean age was 57.0 ± 15.0 years. Overall mean total standardized FCV‐19S and WISQOL scores (both transformed to min‐max 0‐100) were 34.3 and 70.3 respectively. Correlation analysis between the two questionnaires demonstrated a significant inverse correlation (r = ‐0.265, p < 0.05) suggesting that greater fear for COVID‐19 may result in a lower stone‐related quality‐of‐life. A significant difference in fear and QOL scores was observed between the sexes, with women having more COVID‐19 fear (35.8 vs. 28.6, p < 0.01) and lower stone‐related QOL (64.2 vs. 75.2, p < 0.01) compared to men. Quartile ANOVA analysis revealed significant mean difference in WISQOL scores as well as within each domain of the WISQOL questionnaire across all FCV‐19S score quartiles (p < 0.05).

Conclusions: From our study, there appears to be a relationship between the between the fear of COVID‐19 and stone‐related QOL of patients with urolithiasis. Using two validated questionnaires (The Fear of COVID‐19 Scale and the Wisconsin Stone Quality of Life), we found that greater fear for COVID‐19 was associated lower stone‐related QOL.

MP01-15 COVID‐19 Pandemic Results in Decreased Non‐Urgent Urologic‐Related Presentations to the ED

A Balen, J Molino, C Tucci, G Pareek, DW Sobel

Warren Alpert Medical School of Brown University

Introduction & Objective: Urologic‐related visits to the emergency department (ED) are variable in their acuity, ranging from non‐emergent to life‐threatening. We sought to evaluate trends in urologic presentations to the ED during the COVID‐19 pandemic at a tertiary academic institution in the United States to determine the differences in frequency between urgent and non‐urgent visits and further elucidate delayed access to urologic care.

Methods: A retrospective analysis was performed comparing the frequency and type of urologic‐related ED visits at our institution in January‐April 2019 to those in January‐April 2020 during the initial pandemic phase. 1,838 urologic presentations between the two‐time intervals were organized by diagnosis and divided by acuity into urgent and non‐urgent categories. Interrupted time series regression models were used to determine how urologic‐related ED visits changed due to the COVID‐19 pandemic.

Results: The total number of urologic related ED visits by type for each time interval is demonstrated in Table 1. There was a statistically significant drop in total urologic‐related ED visits after the COVID‐19 pandemic began, with a drop in total visits of approximately 76 per month (p = 0.002). There was no difference in the number of urgent ED visits due to the COVID‐19 pandemic (p = 0.13). However, there was a statistically significant decrease in non‐urgent ED visits, with a decrease of 68 visits per month (p = 0.002). When examining the individual visit types, there were no differences in visit volume except for hematuria and nephrolithiasis/ureterolithiasis visits. There was a statistically significant reduction in hematuria‐related ED visits, with a reduction in visits of approximately 11 per month (p = 0.03). Similarly, there was a statistically significant decline in nephrolithiasis/ureterolithiasis‐related ED visits, with a decline of approximately 28 visits per month (p = 0.04).

Conclusions: The COVID‐19 pandemic coincided with a significant decrease in the number of non‐urgent urologic presentations to our institution's ED. Specifically, there was a significant decrease in the number of patients presenting with hematuria and nephrolithiasis‐related issues. There was no significant decrease in the number of urgent urologic consults. Follow up study is indicated to investigate the effect of delayed evaluation for these non‐urgent urologic diagnoses.

MP01-16 Transforming the Urology clinic to a procedure‐oriented center improves the quality of urological care and patient experience

F Hamouche, R Unno, J Ahn, D Bayne, H Yang, M Stoller, E Finlayson, s smith, R Pruthi, J Smith, T Chi

UCSF

Introduction & Objective: The global pandemic of COVID 19 necessitated limitations for in‐person visits to stop the spread of the virus. At our institution, we sought to maintain patient access while delivering safe socially distanced care. We hypothesized that transitioning the clinics into a procedure‐oriented center would create a safer, more efficient model for patient care delivery.

Methods: Transitioning the clinic consisted of adopting Telehealth visits for the majority of patient's consultations while augmenting the use of physical space in the clinic to facilitate urological procedures. Multiple productivity, financial and patients experience metrics were collected between two periods of time defined as P1‐ Pre Covid (Feb‐Jun 2019) and P2 Post‐Covid (Feb‐Jun 2020) and compared. Statistical analysis was performed using the Chi‐Square test and the Z‐test for two independent samples.

Results: The percentage of performed procedures amongst all clinical visits increased in P2 (45% vs 29% p < 0.001). There was an increase in the percentage of new patients scheduled within 5‐ and 14‐days during P2 (71 % vs 46%, p < 0.001, and 55 % vs 41%, p < 0.001) respectively. Total charges and RVUs decreased in P2 but the overall payments were higher compared to P1. This increase in revenue was due to a higher income generated by procedures. CGCAHPS and Press Ganey scores improved in P2 across all domains representing patient experience. This improvement was statistically significant for “Recommend this provider office” (90% vs 85.7% p = 0.01), “Access overall” (56% vs 49% p = 0.02), and “Moving through your visit overall” (59% vs 51% p = 0.007).

Conclusions: Our data suggests that transitioning the urology clinics into a space that is mainly dedicated to outpatient procedures can represent a model that improves the patient's access to care and clinical experience, as well as strategically bolstering financial revenues. This is a more efficient care model that could replace current practice and represent the future of outpatient Urology.

MP01-17 Quality Improvement for Quality of Life: Low‐Dose Buprenorphine Decreased Opioid Utilization Protocol in Robot‐Assisted Radical Cystectomy

LJ Smith, TC Peak, HE Moreland, DB Rukstalis

University of South Carolina School of Medicine

Introduction & Objective: Opioid‐naïve individuals often first encounter narcotics during major surgery such as robot‐assisted radical cystectomy (RARC) for the treatment of muscle‐invasive bladder cancer. Pain management following RARC with full‐agonist opioids has been the cornerstone of analgesia despite associated toxicity and risk for dependence. New literature describes non‐opioid enhanced recovery pathways, yet none define the merits of decreased opioid utilization (DOU) using partial‐agonist opioid low‐dose buprenorphine (LDB; LDB‐DOU protocol). With recent reevaluation of prescribing requirements by the FDA, LDB may become more accessible. We implemented a quality improvement initiative using an LDB‐DOU protocol to assess the feasibility and outcomes of minimized perioperative opioid burden.

Methods: The LDB‐DOU protocol includes standardized recovery pathways, a multimodal analgesia schedule, and shared pain management expectations. Analgesic management was recorded and converted to morphine milligram equivalent (MME) for comparison. Relevant preoperative, operative, and postoperative recovery details were documented to assess clinical milestones for recovery, readmission rates, and pain control. Prior opioid use was identified using the prescription drug monitoring program.

Results: Twenty medically complex patients (CCI 6, ASA 3) followed the LDB‐DOU protocol after admission for palliative or curative RARC with ileal conduit urinary diversion. The median operative time was 342 minutes, blood loss was 300mL, and hospital stay was three days. Respectively, median total dosage of LDB and MME were 0.375mg and 20/day, allowing for advancement to low‐residue diet on postoperative day (POD) two. One patient experienced transient ileus (POD 2) and two faced 30‐day complications (Clavien 2, 3). None required outpatient narcotic management.

Conclusions: The LDB‐DOU protocol allows for perioperative narcotic mitigation and enhanced quality of life. Improvements in clinical milestones of recovery included adequate analgesia, short hospital stays, fast diet advancement, and low incidence of postoperative ileus and 30‐day adverse events. Compared to morphine, LDB is 20‐50 times more potent for pain modulation but offers nominal euphoric reward due to its distinctive receptor‐binding. It delivers a profile of enhanced safety with optimal antinociception. Though further studies are needed, the use of an LDB‐DOU protocol is a feasible alternative to both standard practice and the newer non‐opioid approaches.

MP01-18 Theatre utilisation in the era of COVID‐19

A Brodie, A Pai

Northampton General Hospital

Introduction & Objective: The COVID‐19 pandemic has had wide reaching consequences on all aspects of health care. As the number of coronavirus cases has fluctuated, access to operating theatres has been similarly affected. However, when theatres are available and running, the impact of the pandemic on theatre utilisation needs to be quantified. There is a paucity of data on this topic. The aim of this study is to assess theatre utilisation prior to and during the pandemic.

Methods: A retrospective review of elective urology theatre utilisation during 2020 at a district general hospital was carried out to assess the impact of the COVID‐19 pandemic on theatre utilisation. Data was also collected on the number of procedures and cancellations.

Results: As expected, there were fewer elective procedures during the pandemic compared to pre‐pandemic. The utilisation of those theatres that were open decreased during the pandemic compared to pre‐pandemic levels. However, the efficiency of theatres improved as the pandemic progressed. The number of cancellations per month increased during the pandemic. The increased cancellations during the pandemic were commonly due to patients cancelling, refusing surgery or not attending their scheduled operations. Despite the presence of green elective theatres, where patients are swabbed for COVID prior to entry, the most common reason given was fear of contracting COVID‐19 in hospital.

Conclusions: It is evident that due to the additional complexities of operating during a pandemic that theatre utilisation is 14.4% lower than pre‐pandemic levels. Although this is multifactorial, during the pandemic, the main reason was due to patients cancelling. Measures must be in place to make patients feel comfortable to enter hospitals for elective procedures to reduce the number of cancellations. This will help improve theatre utilisation.

MP01-19 The impact of COVID‐19 on surgical care delivery for patients with urinary stones

J DiBianco, S Daignault‐Newton, J Ludlow, J Phelps, E Ratchford, M Cotant, KR Ghani, CA Dauw, f Urological Surgery Improvement Collaborative

Department of Urology, University of Michigan

Introduction & Objective: During the COVID‐19 pandemic, limits on elective surgical care were instituted by hospitals to preserve resources. Additionally, patients' desire to limit health care contact may impact surgical decision making. We aimed to understand how institutional pressures and patient preference affected the delivery, choice and outcome of ambulatory surgical care for urinary stone disease during the COVID‐19 pandemic.

Methods: Reducing Operative Complications from Kidney Stones (ROCKS) is a quality improvement initiative from the Michigan Urological Surgery Improvement Collaborative (MUSIC) that maintains a prospective clinical registry of ureteroscopy (URS) and shockwave lithotripsy (SWL) cases. Using this registry, we categorized all cases by time frame, defining July 1^st ‐ December 31^st 2019 as preCOVID (PC), March 16^th ‐ June 15^th 2020 as duringCOVID (DC) and June 16^th ‐ September 15^th 2020 as afterCOVID (AC). Patients in each cohort were characterized across a range of sociodemographic and clinical factors. We assessed changes in procedure choice (URS vs SWL), procedure acuity (elective vs emergent), and outcomes (ED visit and hospitalization within 30 days of surgery).

Results: 6375 cases were identified, 4513 URS and 1862 SWL. PC consisted of 3310 cases (2238 URS and 1072 SWL), DC consisted of 1141 cases (888 URS and 253 SWL) and AC consisted of 1924 cases (1387 URS and 537 SWL). A higher proportion of URS cases were performed DC compared to PC and AC (77.8% vs 67.6% vs 72.1%, p < 0.001, respectively). A higher percentage of emergent cases in DC compared to PC and AC (21.8% vs 13.7% vs 15.3%, p < 0.001, respectively). Significantly more cases in DC compared to PC and AC were prestented, had positive UA/urine culture, ureteral stones, had hydronephrosis, were stented and had longer stent dwell time. ED visits and unplanned hospitalizations were not significantly different.

Conclusions: The COVID‐19 pandemic resulted in a lower overall stone treatment rates and higher proportions of URS compared to SWL. Significantly more emergent cases for ureteral stones with positive UA/urine cultures and evidence of obstruction were performed duringCOVID with higher stent placement rates and longer stent dwell times. These data pointing towards preference for higher intensity or acuity cases without differences in unplanned healthcare encounters.

MP01-20 Health Related Quality of Life for Stone Patients During COVID‐19 Pandemic is Significantly Lower than Pre‐Pandemic

MA Knoedler, S Li, SL Best, SP Hedican, KL Penniston, SY Nakada

University of Wisconsin, Department of Urology

Introduction & Objective: The coronavirus disease 2019 (COVID‐19) pandemic has altered many aspects of life including quality of life and the way patients interact with the health care system. We assessed patients with stone disease seen in the urology clinic for health‐related quality of life (HRQOL) prior to and during COVID‐19 utilizing the Wisconsin Stone Quality of Life questionnaire (WISQOL).

Methods: The WISQOL is used routinely in our clinical practice to assess patients' HRQOL at every encounter. Patients seen in clinic with stone disease at a single institution were invited to complete a WISQOL and provide information as to their stone and stone‐related symptom statuses. Responses from patients seen from January 1, 2019 to December 31, 2019 (pre COVID‐19) were compared to patients seen from June 9, 2020 to December 31, 2020 (post COVID‐19). Patients were case matched based on symptomatic status (yes/no/not sure) and gender. WISQOL total and domain scores were standardized to scales of 0‐100. Symptomatic patients, asymptomatic patients and patients who were not sure if they were symptomatic from stone disease were analyzed separately using MANOVA.

Results: A total of 90 patients were included in the analysis (45 pre COVID‐19 and 45 post COVID‐19). In the post COVID‐19 cohort, 14 patients were symptomatic, 27 were asymptomatic and 4 were not sure if they were symptomatic. Symptomatic patients seen post COVID‐19 had statistically lower HRQOL compared to patients pre COVID‐19 (44.8 ± 18.6 vs 62.6 ± 29.2, p < 0.05). HRQOL did not differ significantly pre and post COVID for asymptomatic patients (86.9 ± 21.6 vs 90.4 ± 9.9, p = 0.37) or patients who were not sure if they were symptomatic (98.2 ± 1.3 vs 57.6 ± 42.3, p = 0.308). For patients with symptoms, HRQOL was particularly lower with respect to social functioning and vitality (Table).

Conclusions: Patients seen in urology clinic for stone disease during the COVID‐19 pandemic had significantly lower HRQOL then those seen prior to the onset of COVID‐19.

MP01-21 COVID‐19 pandemic and its effect on supra‐regional extracorporeal shock wave lithotripsy (ESWL) service

M Kay, J Lau, F Jarral, S Rajpal, N Boucher, J Patterson

Royal Hallamshire Hospital

Introduction & Objective: The COVID‐19 pandemic brought significant challenges to all healthcare systems around the world. We studied its impact on our supra‐regional ESWL service.

Methods: Patients who received ESWL using our onsite lithotripter (Storz Modulith SLX‐F2) during the initial National Lockdown (NL) period were compared with those treated over a similar time period in 2019. Patients with renal calculi were excluded for direct comparison as only a small number of patients with renal calculi were treated during NL. As the supra‐regional centre, we continued to provide acute treatment during NL albeit with restricted access due to staff redeployment, and within safety restrictions, and continued to receive patients from other network centres.

Results: 25 patients with ureteric calculi treated in 2019 were compared with 23 patients treated during NL. The mean ages were 56.6 VS 50.0 (2019 VS NL). The mean time to treat were 20.9 VS 19.4 days (2019 VS NL). Two patients' 2nd treatment got delayed during NL. Treatment outcomes are outlined in table 1. The mean residual stone sizes were 4.9mm VS 5.7mm (2019 VS NL). In 2019, complication rate was 16.0% with the commonest being pain (75.0%) when compared to 21.7% during NL (80% pain). Steinstrasse were not seen in either group. One patient treated during NL sustained a moderate peri‐renal haematoma managed conservatively. Treatment parameters such as number of shocks delivered and screening time were equivalent between groups.

Conclusions: COVID‐19 led to pressures on health services and also patients changed their patterns of presentation. Restricted access to the operating theatre made use of non‐invasive treatments an essential part of patient management during the lockdown period. We show equivalent outcomes to normal practicedespite treating larger and potentially more challenging stones, with few complications and while minimising COVID‐19‐related risks to the patient.

MP01-22 #AUAMatch: The Impact of COVID‐19 on Social Media Use in the Urology Residency Match

P Ho, EJ Margolin, E Sebesta, A Small, GM Badalato

Columbia University Vagelos College of Physicians and Surgeons

Introduction & Objective: Social Media (SoMe) use has rapidly expanded within the urological community over the last decade and has become an important tool in the residency application process. SoMe was particularly relevant to medical students during the 2020‐2021 application cycle, as the COVID‐19 pandemic limited in‐person interactions. In this study, we examined changes in SoMe use among urology residency applicants before and after the pandemic.

Methods: We distributed surveys to all individuals who applied to our residency program for application cycles ending in 2018, 2019, and 2021. The surveys included questions about applicants' SoMe use and their perceptions of programs' SoMe use. We evaluated the ways applicants used SoMe during the application process, both before (2018/2019) and after (2021) the COVID‐19 pandemic. The primary outcome was SoMe use for professional purposes.

Results: We received survey responses from 33% (162/496) and 29% (84/294) of applicants from the 2018/2019 and 2021 cohorts, respectively. There was a significant increase in professional SoMe use in the 2021 cohort (80%) compared with the 2018/2019 cohort (44%) (p < 0.001). When controlling for age and gender, applicants in 2021 were more likely to use SoMe for professional purposes (odds ratio 4.68, p < 0.001). Applicants more frequently used Twitter (p < 0.001) and LinkedIn (p = 0.036) and less frequently used Doximity (p < 0.001) in 2021 compared to 2018/2019. In 2021 compared to 2018/2019, a larger proportion of applicants used SoMe to connect directly with residents (69% vs 34%, p < 0.001) and with faculty members (65% vs 15%, p < 0.001). Applicants in 2021 compared to 2018/2019 more often found SoMe to be useful for making decisions about applying to (33% vs 10%), interviewing at (26% vs 7%), and ranking programs (20% vs 9%) (all p < 0.05). Twitter was the most common platform for applicants to access program information, increasing from 38% to 71%. Of the 2021 survey respondents who reported using SoMe, 74% (59/80) reported that application changes due to the pandemic directly caused them to increase their SoMe use. Overall, 31% of applicants felt that SoMe engagement had a positive impact on the application process, and 61% would like to see similar or more interaction between applicants and programs in future cycles.

Conclusions: The COVID‐19 pandemic ushered in a period of unprecedented SoMe usage among urology applicants, who used it to learn about and connect with residency programs in new ways. The use of SoMe by residency programs has become an important component of trainee recruitment and is likely to continue in the future.

MP02-01 Development of the Short Form of the Wisconsin Stone Quality of Life (WISQOL) Questionnaire for Assessing the Health‐Related Quality of Life of Patients with Urolithiasis

KL Penniston, S Li, SY Nakada

University of Wisconsin School of Medicine and Public Health

Introduction & Objective: The 28‐item Wisconsin Stone Quality of Life questionnaire (WISQOL) is a specific, self‐administered, health‐related quality of life (HRQOL) instrument for assessing the impact of urolithiasis. Prior reports confirm the WISQOL's reliability, validity, and responsiveness. Its use has helped to identify specific HRQOL decrements in patients with urolithiasis, including after or between stone events. To address needs of large clinical studies and long‐term monitoring, for which efficiency competes with precision, we developed a short‐form (SF) version of the WISQOL.

Methods: We use the WISQOL in our clinical stone practice. Patients are invited to complete it at every appointment. Data for this study were from patients (n = 704) who completed the WISQOL between June 2017 and February 2020 at a Urology Clinic appointment with either the primary stone surgeon or a nurse practitioner. Of these, 196 had >1 missing item and were excluded. Remaining patients were 53% female, 54 ± 15 y, and mixed for stone history (min‐max, 1 to >50 lifetime stone events). Nearly half (49%) had current stones; 30% were experiencing stone‐related symptoms or had done so within the past 4 weeks. We calculated WISQOL total and domain (n = 40 scores. We used item analysis and factor analysis to evaluate all 28 WISQOL items.

Results: Items with item‐total correlation coefficients <0.84 were eliminated (n = 20). Of the 8 remaining items, linear regression analysis and cross loading identified 6 that best predicted total WISQOL scores (P < 0.001, figure), representing 2 of the 4 WISQOL domains (D1, social; and D2, emotional). Using these items, 80% of patients placed in the same quantile for total score as with the original WISQOL. Item‐score correlation coefficients (original vs WISQOL‐SF) ranged from 0.84‐0.93; correlation with total score was 0.95 (P < 0.001 for all comparisons). The WISQOL‐SF Cronbach alpha coefficient was 0.94 compared to 0.97 for the original WISQOL. Of patients misplaced for quantile by the WISQOL‐SF, 32 and 30% were patients with stones and/or stone symptoms at the time; they tended to score higher for HRQOL with the WISQOL‐SF.

Conclusions: We produced the WISQOL‐SF, a 6‐item version of the WISQOL suitable for efficient assessments. While more testing is needed, the WISQOL‐SF appears best suited for long‐term follow up of HRQOL in stones.

MP02-02 Where do you practice? And its effect on equipment, technique, and more

T Aro, A Smith, A Rai, D Mikhail, D Hoenig, AD Smith, Z Okeke

The Smith Institute for Urology

Introduction & Objective: Endourology is constantly developing with new techniques, modalities, surgical instruments, and perhaps no less important, the surgeon experience and expertise. We looked into differences in basic endourology practice patterns in the united states vs the rest of the world.

Methods: An online questionnaire comprised of 6 categorizing questions, and 31 multiple choice questions looking into common endourologic scenarios and practice pattern was sent using the endourology society contact list.

Results: 279 responses were sorted into 207 from outside, and 72 from inside the USA. In a ureteroscopy setting, responses outside the USA use an access sheath almost always in 64%, compared to 46% in the USA. In PCNL, responses from outside the USA don't have a preferable calyx in 53% and in 30% prefer the lower calyx, compared to 61% and 17% respectively inside the USA. Inside the USA, 83% of responses would use balloon dilators compared to only 30% outside, and 78% prefer the prone position, compared to 52% outside the USA. Lastly, in a prone position setting, 54% of responses inside the USA use vertical placement of the bolsters compared to 31% in the outside the USA group.

Conclusions: Although there are no guidelines or specific recommendation on some of the basic practice patterns, it appears there are many differences between the USA endourologists and the rest of the world. USA practitioners use access sheath less, more likely to choose an entry calyx for PCNL based on case and not a personal preference, use balloon dilators much more, and prefer the prone position. Future, larger scale research might be needed to explain the basis for such differences.

MP02-03 Withdrawn

MP02-04 Racial Disparity in Prostate Cancer Diagnosis: A Comparison of Prostate Biopsy Results in African American and White Men using an MRI based Biopsy Strategy

A Kasraeian, M Alcantara, K Mola Alcantara, J Cesaretti, A Kasraeian

Kasraeian Urology

Introduction & Objective: African American (AA) men in the United States have an increased burden of morbidity and mortality from prostate cancer (PCa). The roles of factors related to both racial disparities and intrinsic biological traits remain to be determined. We quarried our prospective database of standard and MRI fusion biopsies (tMRI/US FPB) to determine if any pre‐biopsy characteristics predicted adverse tumor pathology.

Methods: Between January 2017 and December 2020, 560 men underwent prostate biopsy (PBx) using an MRI based algorithm. Men with negative MRI underwent standard PBx (n = 293), while those with lesion on mpMRI underwent tMRI/US FPB (n = 267). All patients underwent mpMRI of the prostate, interpreted by a single radiologist using the PIRADS scoring system. 3D rendering of the regions of interest was performed by the radiologist prior to tMRI/US FPB performed by a single urologist using the Invivo UroNav Fusion Biopsy System. A standard 14 core PBx was performed at the same time in all tMRI/US FPB cases. Prospective data was collected and analyzed.

Results: Of 560 men who underwent standard and tMRI/US FP with 14Bx (tMRI/US FP‐14Bx), 422 presented with rise in PSA and 182 had a suspicious digital rectal exam. 256/418 (61%) of White men and 62/92 (67%) of AA men were found to have PCa (p = 0.29). 153/418 (37%) of White men and 46/92 (50%) of AA men had a Gleason score of 7‐10 (p = 0.019). Age, DRE status, PIRADS score and the incidence of Gleason 6 PCa were not found to be significantly different by race. 112/415 (27%) of White men and 10/91 (11%) of AA men had a PSA upon presentation of 0‐3.9 ng/ml (p = 0.001). The PSA levels of 4.0‐9.9 ng/ml and PSA >10 ng/ml at presentation were not significantly different. Of the 50/560 men who identify as not White and not Black no significant difference was found for any tested factor but interestingly 12/50 (24%) presented with a PSA between 0‐3.9 ng/ml (p = 0.053 NS) which was very close to the effect seen relative to White men.

Conclusions: In this dataset, it appears that AA men present with a higher PSA than White men. It is likely that this is related to disparities in access to care rather than biological intrinsic factors. We did observe a higher incidence of Gleason 7‐10 which one would expect in a cohort of patients who presented for biopsy in the community with a significantly higher PSA presentation. Continuing education of primary care providers regarding the importance of PSA testing in the AA community should be emphasized by both the urological and primary care professional medical societies.

MP02-05 Economic Burden of Complicated Ureteral Stent Removal in Patients with Kidney Stone in the United States

KR Ghani, S Rojanasarot, B Cutone, S Bhattacharya, AE Krambeck

Northwestern University

Introduction & Objective: Cystoscopy‐based stent removal (CBSR) is a common procedure following ureteroscopy with stent placement. Although the American Urological Association (AUA) designated complicated stent removal CPT ^® code 52315 for encrusted stent removal, no previous research has examined if complicated stent removal is associated with increased healthcare costs to the US healthcare system. This study investigated the economic burden of complicated versus simple stent removal among commercially insured US patients.

Methods: A retrospective cohort study was conducted to identify patients who had ureteroscopy with stent placement for stone disease between January 2014 and June 2018 from IBM MarketScan Commercial database, a nationally representative data sample of the US population with employer‐sponsored health insurance. We included patients who were ≥18 years old and had CBSR within 6 months post‐index ureteroscopy. Patients were categorized as those with simple or complicated CBSR using CPT codes 52310 and 52315, respectively. To understand the patients' profiles, we explored their baseline characteristics and comorbidities. Medical costs of stent removal encounters were calculated and adjusted to 2020 US dollars to estimate the economic burden.

Results: Out of 16,682 patients undergoing ureteroscopy with stent placement, 465 (2.8%) had complicated CBSR. Most patients with simple and complicated CBSR were males (52.9% vs 58.1%; 0.03), aged 55‐64 years (37.5% vs 39.8%; p = 0.08), located in South region (41.2% vs 52.2%; p < 0.0001), and had stone comorbidity (55.4% vs 55.7%; p = 0.95). The mean days to stent removal for simple vs complicated CBSR were 16.5 vs 13.2 (p = 0.0004), respectively. Medical costs of complicated CBSR were significantly higher than simple CBSR ($2,206 vs $1,149; p < 0.0001).

Conclusions: Complicated stent removal is associated with an increased economic burden. Ureteral stents designed to reduce the need for complicated CBSR may provide cost‐savings to the US healthcare system.

MP02-06 Cost‐Effectiveness of Retrograde Intrarenal Surgery, Standard and Mini Percutaneous Nephrolithotomy, and Extracorporeal Shock Wave Lithotripsy for the Management of 1‐2cm Renal Stones

KM Wymer, T Juvet, V Sharma, K Koo, MR Humphreys, AM Potretzke

Mayo Clinic

Introduction & Objective: Options for treating 1‐2cm renal stones include retrograde intrarenal surgery (RIRS), percutaneous nephrolithotomy (PCNL), and extracorporeal shock wave lithotripsy (ESWL). Despite the high prevalence and associated costs of nephrolithiasis, a cost‐effectiveness evaluation comparing these treatment modalities has not been performed.

Methods: A Markov model was created to compare cost‐effectiveness of PCNL, URS, and ESWL for 1‐2cm lower pole renal stones. Stone free, complication, retreatment, and secondary procedure rates were based on a systematic literature review, costs were drawn from 2020 Medicare rates, and quality adjusted life years (QALYs) were assigned from the literature. The incremental cost‐effectiveness ratio (ICER) was compared with a willingness‐to‐pay (WTP) threshold of $100,000/QALY. Univariable and multivariable sensitivity analyses were performed, as were additional analyses for non‐lower pole stones and mini‐PCNL.

Results: At 3 years, mean costs per patient were $10,290 (PCNL), $5,930 (RIRS), and $10,916 (ESWL). PCNL resulted in the highest QALYs at 2.951 compared to 2.946 and 2.943 for RIRS and ESWL, respectively. For lower pole stones, RIRS was most cost‐effective followed by PCNL (ICER $948,101/QALY); ESWL was dominated with higher costs and lower effectiveness. Results were more pronounced for non‐lower pole stones with RIRS dominating both PCNL and ESWL. Lastly, although mini‐PCNL resulted in lower costs ($10,109) and higher QALYs (2.953) compared to standard PCNL, it was still not cost‐effective relative to RIRS with an ICER of $633,228/QALY. The lower pole model was sensitive to the stone free rate (SFR) and cost of each modality. ESWL became cost‐effective with SFR ≥75% or cost < $1,247 and PCNL became cost‐effective if cost ≤$5,086. On multivariable sensitivity analysis, the most cost‐effective strategy was RIRS in 99%, PCNL in 1%, and ESWL in 0% of simulations.

Conclusions: For 1‐2cm renal stones, RIRS is the most cost‐effective approach. However, at lower costs, PCNL could become more cost‐effective, particularly for lower pole stones. Additionally, mini‐PCNL offers a promising alternative warranting further investigation.

MP02-07 Seasonal Variations in Inpatient Pediatric Admissions for Urolithiasis

R Alam, W Wu, BR Matlaga, JS Winoker

Johns Hopkins University School of Medicine

Introduction & Objective: It is believed that higher temperatures in the summer months are associated with increased risk of stone formation and subsequent utilization of hospital resources, including inpatient admission. However, these observations have been derived primarily from the adult population. We sought to examine if this purported association between seasonal temperature changes and inpatient stone admissions extends to the pediatric population.

Methods: The most recently available Kids' Inpatient Database (KID) from 2016 was used to estimate nationwide pediatric inpatient admissions in the United States. Patients with a stone‐related admission were identified based on hospital billing codes. KID was linked to temperature data from the National Oceanic and Atmospheric Administration (NOAA) to identify the average monthly temperature at the time and location of admission. Admissions were grouped into seasons: winter (December‐February), spring (March‐May), summer (June‐August), and fall (September‐November). This analysis was replicated using the National Inpatient Sample (NIS) from 2016 to evaluate associations in the adult population as a frame of reference.

Results: There were 6.27 million pediatric inpatient admissions in 2016, of which 8502 (0.14%) had a stone diagnosis. Although the summer months were warmer, there was no significant difference in the number of inpatient stone admissions based on season. Furthermore, there was no significant association between stone admission and temperature (RR 1.00 per degree Fahrenheit, P = 0.15). In adults, however, there was a significant association between inpatient stone admissions and season (P < 0.001), with an increase seen in the summer months. Furthermore, the risk of stone admission increased by 1% with every degree increase in temperature (RR 1.01 per degree Fahrenheit, P < 0.001).

Conclusions: Consistent with prior observational data, increased temperatures were associated with an increased risk of admission in adults. However, there was no observed relationship with seasonal temperature in the pediatric population. This may underscore the differing physicochemical factors driving lithogenesis in children, as compared to adults.

MP02-08 Analysis of urological discussions on Reddit: an emerging platform for patient‐to‐patient information, advice and support

KT Ravivarapu, EB Garden, A Small, O Al‐Alao, MA Palese

Icahn School of Medicine at Mount Sinai

Introduction & Objective: Reddit is a website that hosts thousands of niche discussion boards (subreddits) that are user‐driven and managed. The use of other online platforms such as YouTube and Twitter in urology has been well documented, but the presence and nature of urological discussions on Reddit has not been explored. Here, we aim to present an overview of urology related subreddits with usage statistics and growth trends.

Methods: A scoping search of Reddit was performed for common urological conditions. Nine subreddits with substantial usage were identified: reddit.com/r/interstitialcystitis, r/kidneystones, r/maleinfertility, r/testicularcancer, r/prostatitis, r/prostatecancer, r/erectiledysfunction, r/incontinence, and r/varicocele. Data for each urology related subreddit were obtained from the website subredditstats.com with results updated through March 13, 2021.

Results: All 9 urology related subreddits showed an upward trend in number of users (Figure 1). The interstitial cystitis subreddit had the largest user base (8791 users), followed by erectile dysfunction (6781 users), kidney stones (5983 users), prostatitis (4152 users), male infertility (3153 users), testicular cancer (2762 users), varicocele (2746 users), prostate cancer, (1767 users), incontinence (1218 users). These subreddits had between 2 and 15 new posts per day and 5 and 98 comments per day. Of the top 5 posts on each board, common post types emerged: patient experience stories (57.8%), humor (24.4%), and pictures (17.8%).

Conclusions: Patients use the anonymous online forums Reddit to share unbiased and uninhibited real world experiences. Urology related discussions on Reddit are increasing rapidly and will only continue to expand as a technology focused generation joins the urologic patient population. While a wide variety of urologic conditions are represented on Reddit, conditions that affect younger patients seem to have larger presence. Future analysis of online patient discussions can facilitate better patient care by offering insights into prevailing concerns, common misconceptions, and patient experiences.

MP02-09 Understanding patients' concerns regarding kidney stones using quantitative thematic analysis of social media

KT Ravivarapu, A Small, EB Garden, M Levy, O Al‐Alao, MA Palese

Icahn School of Medicine at Mount Sinai

Introduction & Objective: Analysis of online patient discussions can offer insights into concerns, attitudes and misconceptions from unfiltered and unbiased datasets. We identified key themes and insights from kidney stone patients on Reddit, one of the world's most popular online discussion forums, using quantitative natural language processing (NLP).

Methods: We extracted 3 years of posts (8/2016‐8/2019) and comments (1/2017‐12/2019) from the Reddit community r/kidneystones with 6,010 members. Computational NLP analysis was performed using the meaning extraction method with principal component analysis (MEM/PCA) to identify discussion topics and their relative frequencies (Fig. 1). Kaiser‐Meyer‐Olkin Measure of Sampling Adequacy (KMO) and Bartlett's test were calculated to validate methods.

Results: 2,009 posts and 18,255 comments were analyzed. Overall, patients use this space to crowdsource medical information, diagnoses, and emotional support. The six key themes included: lifestyle/emotional impacts, dietary modifications, symptoms, medical evaluation, surgery/procedures, and pharmacotherapy/alternative therapies. Common terms in the lifestyle/emotional impacts cluster included scared (4.3%), anxiety (2.7%), and stress (1.8%). Dietary modification posts mentioned water (22.1%) and lemon (3.2%). Symptom posts overwhelmingly commented on pain (67.5%) and blood (21.2%). Regarding surgery/procedures, lithotripsy (7.9%) was mentioned more than ureteroscopy (5.3%) or PCNL (1.1%). Discussion of pharmacotherapy/alternative therapies commonly included [tamsulosin] (9.4%) and pain relievers like ibuprofen (3.4%), morphine (3.4%), [oxycodone] (1.6%) and [phenazopyridine] (1.1%). Interestingly, alternative therapies were mentioned in the same cluster, including beer (1.2%) and chanca [piedra] (1.1%).

Conclusions: Kidney stone patients use social media communities to share their real world experiences. NLP offers robust statistical methods to characterize prevailing themes of discussion online. Familiarity with the content of these discussions may allow providers to improve shared‐decision making, patient satisfaction, and quality of care.

MP02-10 Thulium laser enucleation of the prostate versus open prostatectomy: A prospective cost analysis

M Maltagliati, L Berti, U Besana, A Calori, C Buizza, S Micali, BC Rocco, M Sighinolfi, G Bozzini

ASST Valle Olona

Introduction & Objective: Thulium laser enucleation of the prostate (ThuLEP) has emerged as an alternative to open prostatectomy (OP) and is recommended in EAU Guidelines for Prostate bigger than 80 ml. Short‐term results demonstrate minimal morbidity making it safe for patients with prostates of any size, leading to a decrease in hospital stay. The objective of this study is to compare the cost of OP with ThuLEP in the treatment of bladder outlet obstruction (BOO) attributed to benign prostatic hyperplasia.

Methods: From January 2015 to January 2017 a total of 150 consecutive and equivalent patients with large prostate (80 to 300 ml) and documented BOO underwent surgical treatment with either OP (75 in Group 1) or ThuLEP (75 in Group 2). All costs associated with the procedures during the hospital stay and at least 1 year follow up including routine office visits and management of complications were assessed prospectively. A cost analysis of each individual clinical event was performed.

Results: Two groups were set up for the cost analysis. Group 1 for OP, Group 2 for ThuLEP considering a 5 year amortization purchase program. The cost analysis showed a mean cost of 4.407 € for group 1; and 4.047 € for group 2 (Table 1).

Conclusions: ThuLEP is associated with a significant net cost saving compared with OP, in patients undergoing surgery for symptomatic benign prostatic hyperplasia in large glands, especially in a long term purchase program.

MP02-11 Seasonal variation in the incidence of acute renal colic

A Alkhayal, O Alfraidi, T Almudlaj, A Nazer, N Alboqami, K Alrabeeah, AH Alathel

Schulich School of Medicine & Dentistry, Western University

Introduction & Objective: Urolithiasis is one of the most common medical diseases affecting the general population. Many epidemiological studies have shown association between geographic area with high mean daily temperature and urolithiasis disease. However, it is unclear if the seasonal variation within high temperature geographical area will affect the acute presentation of renal colic to the Emergency department (ED). The aim of this study is to identify the influence of seasonal variation in the acute presentation with urolithiasis disease.

Methods: In this retrospective study, the database in King Abdullah International Medical Research Center (KAIMRC), Riyadh, Kingdom of Saudi Arabia has been reviewed in the last 4 years. All patients that have presented with renal colic and have been diagnosed with urolithiasis by non‐contrast enhanced CT scan have been included in our study.

Results: A total number of 1057 patients have been enrolled in this study . 753 (71.24%) were males and 304 (28.76%) were females, with a mean age of 42.33 ± 16.12 years. Most of the patients presented in summer (31.22%), followed by spring (26.87 %), fall (24.12%) then winter (17.79%) respectively. Most of the patients (84.77%) presented with ureteral stones, while (15.23%) presented with kidney stones. (78.33%) of patients have no history of previous stone formation, while (21.67%) of patients were recurrent stone former.

Conclusions: Acute presentation with urolithiasis is higher during summer followed by spring, fall then winter respectively. Public educational program is highly recommended to increase awareness about stone formation and appropriate methods to avoid it. To this end, further study is needed to know the stone composition and appropriate methods to avoid developing urolithiasis.

MP02-12 Health‐Related Quality of Life Disparities among Hispanic/Latinx Patients with Nephrolithiasis

AR Flores, G abedi, C Girgiss, KL Penniston, S Li, D Norena, DF Friedlander, SK Bechis, RL Sur

Introduction & Objective: It is documented that Hispanic/Latinx kidney stone formers have inferior health‐related quality of life (HRQoL) compared to the general population.^1‐3 We hypothesized that socioeconomic factors are primary drivers of this finding. Our objective was to identify factors that explain HRQoL discrepancies among Hispanic/Latinx stone formers.

Methods: This was a prospective cohort observational study of patients with kidney stones at UC San Diego Health who were enrolled over 2 years from June 2018 to August 2020. Patients enrolled completed a validated English or Spanish copy of the Wisconsin Stone Quality of Life questionnaire (WISQoL) based on their language preference. Patient characteristics and self‐reported HRQoL were compared between Hispanic/Latinx and non‐Hispanic/Latinx stone formers. Matched and unmatched group comparisons were performed based on age, gender, body mass index, stone symptoms, and insurance type.

Results: A total of 270 patients were enrolled (Hispanic/Latinx n = 88; non‐Hispanic/Latinx n = 182). Hispanic/Latinx stone formers had higher rates of public insurance at baseline (p < 0.001) with significantly lower HRQoL [social impact (p = 0.007), emotional impact (p = 0.005)]. However, a matched cohort comparison demonstrated no differences.

On multivariate analysis, patients with private insurance had double the likelihood of having higher HRQoL (OR 2.21, 95% CI 1.12‐4.02, p < 0.05). Stone symptoms (OR = 0.06, 95% CI 0.03‐0.14, p < 0.001) and ED visits (OR = 0.04, 95% CI 0.228‐0.803, p = 0.008) were associated with lower HRQoL. Ethnicity was not a significant factor in quality of life scores on multivariate analysis.

Conclusions: Our analysis suggests that differences in HRQoL amongst Hispanic/Latinx stone formers are primarily driven by socioeconomic factors as opposed to clinical differences. Specifically, source of insurance appears to have significant effect on HRQoL in this ethnic group.

MP02-13 What is the kidney stone related nephrectomy prevalence in an emerging country?

V Dall'Aqua, R Borges, A Rodrigues, A Lopes Neto

Introduction & Objective: Kidney stone disease is a preventable renal failure etiology. However, this management could be an important public health concern in emerging countries. To access the local scenario about stone related nephrectomy, we review our data from a tertiary center.

Methods: Medical records from three hospitals integrated to ABC Medical School, at Santo Andre ‐ Brazil, were reviewed including 2008 to 2019 data. All nephrectomies were accessed, however partial nephrectomies were excluded after first analysis.

Results: There were performed 398 nephrectomies between 2008 to 2019. From these cases, 62 (15.5%) were partial nephrectomies. Ninety‐eight surgeries (29.1%) were due kidney stone disease and more than one third of the patients (35.7%) was admitted without renal failure, but they lost the kidney function on behalf of public health program slowness.

Conclusions: Brazilian National Health Program should improve the patients access to urology team and measures to prevent kidney stones development, once upon this is a very prevalent disease and an important renal failure preventable etiology.

MP02-14 Withdrawn

MP02-15 Trends in the Influence of Gender, Race, and Ethnicity on the Prevalence of Kidney Stones: A Multi‐Institutional and Claims Analysis

J Crivelli, N Maalouf, P Yan, A Hughes, R Hsi, NE Canvasser, N Kachroo, D Leavitt, K Wood, G Oates, JM Hollingsworth, DG Assimos

The University of Alabama

Introduction & Objective: Significant increases in kidney stone prevalence have been reported for Black and Hispanic individuals in the US, but the gender‐specific contribution to this trend is unclear. We evaluated the distribution of prevalent stone disease by gender, race, and ethnicity in contemporary cohorts.

Methods: We identified patients with a kidney stone diagnosis between 2010‐2019 from three centers (University of Alabama at Birmingham [UAB, n = 32,745], University of Texas Southwestern [UTSW, n = 51,354], and Parkland Memorial Hospital [PMH, n = 22,967]). We also utilized a claims database (Optum Clinformatics Data Mart) to identify working‐age adults with a kidney stone diagnosis from 2010‐2019 (n = 68,594). Differences in male‐to‐female ratio between groups across all datasets were assessed with the Mann‐Whitney U test. In the Optum cohort, temporal trends in male‐to‐female ratio were modeled with linear regression.

Results: In each cohort, most Black stone formers were female, most White stone formers were male, and most non‐Hispanic stone formers were male; in two of the four cohorts, most Hispanic stone formers were female (Figure 1). We observed a significant difference in male‐to‐female ratio between Black vs. White stone formers, but not between Hispanic vs. non‐Hispanic stone formers (Figure 1). In the Optum cohort, a significant linear decline in male‐to‐female ratio was observed in White and non‐Hispanic stone formers, but not in Black and Hispanic stone formers (Figure 2).

Conclusions: An analysis of multi‐institutional and claims data showed that most Black stone formers were female, whereas most White stone formers were male, demonstrating a significant difference in gender distribution. Based on insurance claims, the male‐to‐female ratio decreased in all groups over time, but most consistently among White and non‐Hispanic patients. Further evaluation of these findings and their association with comorbidities and socioeconomic factors is needed to understand disparities in stone disease.

MP02-16 Withdrawn

MP02-17 The Social Impact of Surgery for Nephrolithiasis: Results from the Endourological Society TOWER Research Collaborative

AE Jones, G Lin, H Stambakio, BH Chew, JM Stern, JB Ziemba

University of Pennsylvania Perelman School of Medicine

Introduction & Objective: Nephrolithiasis is among the most common urological conditions; however, the social impact of the disease remains significantly understudied, particularly following surgical intervention. We prospectively captured patient‐reported ability to participate in social roles and activities in patients following ureteroscopy (URS) or percutaneous nephrolithotomy (PCNL) for nephrolithiasis.

Methods: Adults undergoing URS or PCNL for renal/ureteral stones were eligible for inclusion (10/2020‐1/2021). Patients prospectively completed PROMIS‐Ability to participate in social roles and activities instrument pre‐operatively (POD 0) and via email on POD 1, 7, and 14. Scores are reported as T‐scores (normalized to US pop., mean = 50) with a change of 5 (0.5 SD) considered clinically significant.

Results: A total of 33 patients completed enrollment at POD 0 (POD 1 = 21, POD 7 = 21, POD 14 = 15). For the overall cohort, there was a clinically and statistically significant difference in scores over each subsequent time comparison (repeated measures ANOVA; p < 0.001). Repeated measures ANOVA show statistically significant difference in scores over each subsequent time comparison for URS patients (p = 0.003), but not PCNL patients (Figure 1). URS patients return to baseline social participation by POD 14, but PCNL patients do not see a return to baseline. Among the entire cohort, increasing age was predictive of greater social participation preoperatively (CI: 0.02–0.66; p = 0.04) and at POD 1 (CI: 0.06 – 0.86; p = 0.03).

Conclusions: Ability to participate in social roles and activities declines immediately post‐operatively. URS patients see normalization in social participation by POD 14, but PCNL patients experience social interference for longer than 14 days. Results offer meaningful insight to assist counseling patients for surgical treatment of nephrolithiasis.

MP02-18 Contemporary practice patterns of transurethral therapies for benign prostate hypertrophy: Results of a worldwide survey

MS Lee, M Assmus, DK Agarwal, T Large, AE Krambeck

Northwestern University Feinberg School of Medicine

Introduction & Objective: Benign prostatic hypertrophy (BPH) is one of the most common medical conditions affecting men. The most recent AUA and EAU guidelines on BPH/LUTS offer Urologists the ability to choose from multiple options. The guidelines offer recommendations based on prostate volume, bleeding risk, and side effect profile, but otherwise give Urologists the freedom to choose. With so many transurethral surgical therapies available, the surgical and postoperative management practices of urologists are unknown. Herein, we present the results of a contemporary global survey on practice patterns of transurethral BPH therapies.

Methods: A REDCap survey was distributed to the ∼3500 members of the Endourological Society. Surgeons completed demographic information. Surgeons selected the BPH therapies they perform ≥10 cases/year. There were four categories of BPH therapies: ablation, enucleation, resection/vaporization, and MISTs. Within each category, there were subcategories to account for different energy modalities. All statistical analyses were performed using SAS 9.4 (2019. Cary, NC).

Results: A total of 175 surgeons responded to our survey. Prostate resection/vaporization remained the most commonly utilized category (n = 147/283, 51.9%) followed by enucleation (n = 64/283, 22.6). Within each category, Bipolar TURP (bTURP) was the most common modality for prostate resection (n = 102/147, 69.4%). Holmium laser enucleation (HoLEP) was the most common modality for enucleation (n = 30/64, 46.9%). Urolift ^® was performed more often than Rezūm^™ (n = 19/34, 55.9% vs. n = 15/34, 44.1%). Among surgeons performing ablation, country of practice was a significant variable for LOS (p < 0.0001). For surgeons performing enucleation, academic urologists and those who had completed a fellowship predicted POD1 catheter removal (p = 0.0240 and p = 0.020, respectively).

Conclusions: In this contemporary, global survey of the Endourology society, resection/vaporization techniques remain the most commonly performed surgical BPH therapies. Rates of MIST remained relatively low at 12.0%. 73.7% of Urolift^®, 66.7% of Rezūm^™, and 60% of Aquablation^® procedures were performed as outpatients.

MP02-19 Impact of flow disruptions on mental workload and performance during Percutaneous Nephrolithotomy

S Hussain, SM Nazim, M Ather, N Zahid, M Ather

Aga Khan UNiversity

Introduction & Objective: To study the impact of intraoperative disruptions on surgeons' mental workload and performance during percutaneous nephrolithotomy (PCNL).

Methods: A structured standardized tool was used to identify disruptions and interference during 33 PCNL procedures. The surgical steps during PCNL were divided into 4 phases i.e., ureteric catheter placement, puncture and tract dilation, intra‐calyceal navigation and stone fragmentation and tube placement. Surgeons' workload was evaluated using a validated tool i.e. Surgery Task Load Index (SURG‐TLX), and correlated with the mean observed intraoperative disruptions. All operating team members evaluated teamwork immediately after the procedure. Statistical analysis was done on SPSS version 22.

Results: A total of 1897 disruptions were observed, with an average of 57.48 ±16.36 disruptions per case. The highest number 32.06 ±14.12 were observed during phase III (Lithotripsy). Most disruptions were due to people entering or exiting operating room (OR) 29.1 + 10.03/ case followed by ringing phone or pagers 6.42 + 2.4. Mean observed intraoperative disruptions were significantly associated with surgeon's mental workload, with people entering or exiting OR being the most frequent disruptions, showed its impact on all domains of surgeons' mental workload measured by SURG‐ TLX. Compared to other team members, surgeons' assistant experienced inferior teamwork (r = ‐0.433; p = 0.012.

Conclusions: Significant intraoperative disruptions were observed during PCNL and correlated with surgeons' workload and have negative impact on the teamwork. Improving operating room dynamics by reducing unnecessary disruptions would help establish efficient and smooth surgical work environment for safe surgical care.

MP02-20 Racial Differences in Utilization of Cytoreductive Surgery among Metastatic Renal Cell Carcinoma Patients Receiving Systemic Therapy

A Becerra, D Cao, N Buac, M Greydanus, M Sturgis, C Feng, C Coogan, E Cherullo, S Vourganti, A Stephenson, AK Chow

Rush University Medical Center

Introduction & Objective: Systemic targeted therapy (STT) is considered first‐line treatment for the management of metastatic renal cell carcinoma (mRCC), which presents in 3 out of 10 patients diagnosed with RCC. National guidelines also support the role of initial cytoreductive surgery (CS) in combination with STT in suitable patients with favorable risks given the potential benefit in overall survival in this population. There is a paucity of literature examining contemporary utilization of CS with STT and whether it varies among racial subgroups. The objective of this study was to evaluate whether racial differences exist in the use of CS among mRCC patients receiving STT.

Methods: Clinical stage IV RCC patients who received STT were identified in the National Cancer Database (2006‐2017). Patients were categorized as undergoing CS+STT vs. STT. Racial subgroups that were evaluated were White, Black, Hispanic, and Other. A multivariable logistic regression was used to assess the association between race/ethnicity and utilization of CS+STT while controlling for patient, tumor, and hospital factors.

Results: We identified 21,763 mRCC patients who met inclusion criteria, of which 29% underwent CS. Black, Hispanic, and Other patients comprised 9%, 7%, and 3% of the cohort, respectively. The unadjusted rates of CS utilization among White, Black, Hispanic, and Other patients were 29%, 22%, 29%, and 30%, respectively and remained stable over time. In adjusted models, independent of patient, tumor, and hospital factors, the only racial differences were that Black patients had 29% lower odds of undergoing CS compared to White patients (OR = 0.71, 95% CI = 0.61‐0.81). Other factors associated with lower CS utilization were older age, Medicaid/no insurance (compared to private), nonacademic hospitals, and urban/rural residence (compared to metro). Black patients experienced worse 5‐year overall survival (HR = 1.11, p = 0.01).

Conclusions: The use of CS for mRCC in the STT era has remained stable for all patients, yet Black patients are still less likely to undergo CS. These effects were not explained by differences in income, education, insurance, or other sociodemographic factors. Given that the survival benefit of CS may only be seen in select populations, it Is unclear whether lower utilization of CS among Black patients reflects specific patient selection criteria or is a product of other patient factors that are difficult to capture in analysis, such as differences in access to health care, certain comorbid conditions, or varying patient attitudes towards surgical intervention.

MP02-21 Withdrawn

MP02-22 Five Year Survival Outcome Comparison amongst Patients with Unfavorable vs. Favorable Renal Cell Carcinoma Subtypes

D Roadman, A Becerra, N Buac, M Greydanus, M Sturgis, D Cao, C Coogan, E Cherullo, S Vourganti, A Stephenson, AK Chow

Rush University Medical Center

Introduction & Objective: Renal cell carcinoma (RCC) tumors vary widely with respect to oncologic risk and are composed of heterogenous histological subtypes that can affect treatment decisions and patient management. While they are rare, certain RCC histologies may possess inherent biological features that make them more aggressive at presentation and throughout treatment. However, no study has quantified the long‐term survival differential between favorable and unfavorable RCC histologies.

Methods: Clinical or pathological stage I‐IV RCC patients who underwent partial or radical nephrectomy were identified in the National Cancer Database (2004‐2017). Patients were categorized as having unfavorable (medullary cell, collecting duct, unspecified) and favorable histologies (papillary, chromophobe, cystic, and clear cell). 5‐year overall survival was compared between those with favorable vs. unfavorable histology using Kaplan‐Meier curves and a multilevel Cox proportional hazards models to account for clustering by hospital. Propensity score matching was conducted to adjust for confounding by patient, treatment, tumor, and hospital factors.

Results: We identified a total of 282,623 RCC patients who met inclusion criteria, of which 839 (< 1%) were unfavorable histologies. Overall, median follow‐up was 4.6 years. The 5‐year survival rates among those with favorable and unfavorable were 75% (95% CI = 74%‐76%) and 39% (95% CI = 38%‐40%), respectively (Figure 1). In propensity score matched models, unfavorable histologies were associated with worse 5‐year overall survival (HR = 1.75, 1.71‐1.80). Results were consistent when individual unfavorable histologies were compared to favorable histologies. Medullary cell (HR = 1.82, 1.65‐2.02), collecting duct (HR = 1.65, 1.58‐1.75), and unspecified RCC (HR = 1.71, 1.44‐2.10) were associated with worse 5‐year overall survival compared to favorable histologies.

Conclusions: In this large national study of RCC patients who underwent partial or radical nephrectomy, unfavorable histologies have almost a 2‐fold higher risk of dying within 5 years. These effects were independent of tumor characteristics such as grade, T, N, and M stage suggesting that unfavorable histologies are mechanistically different than favorable histologies. These results have implications for developing personalized therapies that target high‐risk, aggressive tumors that are otherwise reasonable to manage.

MP03-01 Three‐Year Outcomes after Aquablation Compared to TURP: Efficacy and Ejaculatory Improvements Sustained

PJ Gilling

Urology Bay of Plenty

Introduction & Objective: To compare three‐year (last follow‐up of the protocol) safety and efficacy outcomes after Aquablation or transurethral resection of the prostate (TURP) for the treatment of lower urinary tract symptoms (LUTS) related to benign prostate hyperplasia (BPH).

Methods: 181 patients with BPH were assigned at random (2:1 ratio) to either Aquablation or TURP. Patients and follow‐up assessors at each site were blinded to treatment. Assessments included International Prostate Symptom Score (IPSS), Male Sexual Health Questionnaire (MSHQ), International Index of Erectile Function (IIEF) and uroflow.

Results: At three years, IPSS scores improved by 14.2 points in the Aquablation group and 15 points in TURP (p = .7050, 95% CI for difference −3.6 to 5.3 points). Three‐year improvements in maximum flow rate (Qmax) were large in both groups at 10 and 9.7 cc/sec for Aquablation and TURP, respectively (p = .9078, 95% CI for difference −2.9 to 6.4). Sexual function as assessed by MSHQ‐EjD was stable in the Aquablation group and decreased slightly in the TURP group; these changes persisted at year 3. At three years, PSA was reduced significantly in both groups but showed no difference between groups (p = .4074 for difference). The average annual retreatment occurrence was less than 2% in both treatment groups.

Conclusions: Three‐year efficacy outcomes after TURP and Aquablation were similar and the rate of surgical retreatment was low and similar to TURP. Efficacy results have maintained their improvement since the 90 day follow‐up for both groups that are consistent with all other resective surgical techniques.

MP03-02 The OPEN WATER trial: Aquablation in a real‐world setting 1 year follow‐up

PJ Gilling

Urology Bay of Plenty

Introduction & Objective: Waterjet‐based prostate ablation(the Aquablation procedure) is an increasingly utilized treatment world‐wide for the treatment of symptomatic benign prostatic hyperplasia (BPH). The study was designed to investigate the safety and effectiveness of the Aquablation procedure in a real‐world setting.

Methods: Prospective multi‐national 5‐center single‐arm study with follow‐up to date of 1 year. Sites in New Zealand, Australia, England, Lebanon and Germany enrolled patients.

Results: 178 men underwent the Aquablation procedure at 5 international sites. Mean prostate volume was 60cc. Procedure time averaged 24 minutes and total anesthesia duration was 50 minutes. Five patients (2.7%) underwent blood transfusion in the first week after the procedure; of these, one was for delayed (day 6) bleeding. Prostate volume assessed with transrectal ultrasound decreased 36% by month 3. International Prostate Symptom Score (IPSS) decreased from 21.6 at baseline to 6.1 at 1‐year follow‐up, a 15.5‐point improvement (p < .0001). Maximum urinary flow rate increased from 10.1 at baseline to 21.4 cc/sec at 1 year (an increase of 9.9 cc, p < .0001). No surgical retreatments have occurred due to BPH symptoms.

Conclusions: Real‐world evidence shows that the Aquablation procedure is safe and effective for the treatment of symptomatic benign prostatic hyperplasia. Transfusion rates are higher than other minimally invasive therapies. Trial registration: ClinicalTrials.gov number, NCT02974751.

MP03-03 Pulsed thulium laser enucleation of the prostate (ThuLEP) utilizing a novel pulsed Thulium:YAG laser: first clinical results

C Netsch, B Becker, CM Rosenbaum, AJ Gross

Department of Urology, Asklepios Hospital Barmbek, Hamburg, Germany

Introduction & Objective: A novel pulsed Tm:YAG laser has been introduced for endoscopic enucleation of the prostate (EEP). Aim of this study was to evaluate the safety and efficacy of a pulsed Tm:YAG laser for thulium laser enucleation of the prostate (ThuLEP) in patients with symptomatic benign prostatic obstruction (BPO).

Methods: 41 consecutive patients, undergoing ThuLEP at our institution between September and December 2020, were evaluated prospectively. ThuLEP was carried out using a pulsed 2μm 150‐W Tm:YAG laser (RevoLix^® HTL, LISA Laser products, Katlenburg, Germany) at 100‐W (200 Hz, 0.5 J). Depending on lobe configuration and size of the prostate, a 1‐ or 2‐lobe technique was performed. The baseline parameters, perioperative parameters, immediate functional outcomes (International Prostate Symptom Score (IPSS), Quality of Life (QoL), maximum urinary flow rate (Qmax), post‐void residual urine (PVR)), and the incidence of complications were assessed, respectively. The perioperative complications were noted and classified according to the modified Clavien classification system. Patient data were expressed as median (interquartile range) or numbers (%).

Results: Median age was 72 (63‐75) yrs, preoperative prostate volume was 60 (47.5‐98.5)ml and ASA score 2 (2‐3). A total of 8 patients (19.5%) were treated under continuous antiplatelet therapy (aspirin), while anticoagulant/antiplatelet therapy was temporarily stopped in 11 (26.8%) patients. Total operation time was 44 (29.75‐61.25) min, and the enucleation time 13.33 (8.27‐15.96) min, respectively. Median resected weight was 50 (25‐91) gm, haemoglobin decrease 2 (1.1‐3) g/dl, catheter time 2 (2‐2.75) days and postoperative stay 3 (3‐4) days. Clavien 1 (19.5%), Clavien 2 (7.3%), Clavien 3b (4.9%), and Clavien 4a (2.4%, n = 1, allergic shock due to analgesics) complications occurred. At discharge, Qmax (10.6 vs. 18.9 ml/s), PVR (130 vs. 35 ml), IPSS (21 vs. 13), and QoL (5 vs. 2) differed significantly from baseline (p < 0.001).

Conclusions: The pulsed Tm:YAG laser is safe and effective for EEP in patients with symptomatic BPO. Prospective studies are necessary to assess the value of this new laser device for EEP.

MP03-04 Aquablation vs. thulium laser enucleation of the prostate (ThuLEP): early functional results of a matched‐paired analysis

B Becker, K Vogt, AJ Gross, CM Rosenbaum, C Netsch

Department of Urology, Asklepios Hospital Barmbek, Hamburg, Germany

Introduction & Objective: The aim of this study wastocompare the complications and early functional outcomes afteraquablationwith an established laser enucleation procedurein the therapy ofbenign prostatic hyperplasia (BPH).

Methods: Based on the prostate volume, 44 patients that were treated with aquablation were matched with 44 patients who received a ThuLEP procedure. ThuLEP wasperformed with a2 μm (vela^®XL, StarMedTec, Starnberg, Germany) thulium laser (90‐W) andaquablation therapy with the AquaBeam system(PROCEPT BioRobotics, Redwood Shores, USA). All data are expressed as median (interquartile range).

Results: The prostatevolume was 70 (45‐86) ml. The surgical time did not differ significantly between ThuLEP andaquablation with 44.5 and 42 min, respectively. The hemoglobin drop after aquablation was significantly higher compared to ThuLEP (‐2 vs. ‐1.5 g/dl, p < 0.02). At discharge, IPSS(21 and 20.5 vs. 14 and 9) and QoL (4 and 5 vs. 3 and 2) improved significantly after ThuLEP and aquablation (p < 0.001), with QoL being significantly lower after aquablation therapy (5 vs. 2, p = 0.018). The catheterizationand hospitalization timewere 2 and 3 daysin both groups, respectively(p = 0.5). Reoperationswere necessary in 3 patients (6.5%) afteraquablation and in 2 patients (4.5%) after ThuLEP. Urinary retentionoccurredin 4 patients (8.7%)after aquablation and in 2 patients (4.5%) after ThuLEP. 3 patients (6.5%) that were treated with aquablation developed a urinary tract infection. 5 patients (10.9%) after aquablation developed a postoperative bladder tamponade that could be evacuated via catheter, however, no patient after ThuLEP (p < 0.05).

Conclusions: Aquablation and ThuLEP are fast and safe procedures with immediate micturition improvement postoperatively. Bleeding‐related complications after aquablationoccur more frequently in comparison to thulium laser enucleation of the prostate.

MP03-05 Prostatic Urethral Lift (PUL) demonstrates real world effectiveness in subjects with obstructive median lobes

NJ Barber, KL Ng, G Eure, D Grier, M Rochester, D Rukstalis

Frimley Park Hospital

Introduction & Objective: Results from the MedLift trial revealed prostates with middle lobe obstruction can be treated safely and effectively with the minimally invasive PUL procedure. Utilizing the real‐world retrospective (RWR) study of PUL, we assess outcomes of the treatment in subjects with obstructive middle lobes (OML), compared to subjects with obstructive lateral lobes (LL) only and MedLift results

Methods: 2090 patients across 18 USA and Australian sites who underwent PUL after market clearance through May 2019 were included in the RWR database. Patients were filtered for non‐retention status at baseline and stratified into OML (n = 228) or LL (n = 1311) cohorts. Baseline demographics were compared between RWR OML vs. RWR LL and MedLift subjects. Absolute IPSS, QoL, Qmax, and PVR were evaluated at 1, 3, 6, and 12 months post‐PUL. Adverse events of RWR OML subjects were calculated. All outcomes were compared to RWR LL subjects and absolute IPSS was compared to MedLift OML.

Results: RWR OML subjects were on average 69.8 y.o. with larger prostate volumes (53.3cc ±21.3) than RWR LL (45.4cc ±19.6) and MedLift (44.2 ± 11.2) subjects, and lower baseline IPSS (19.5 ± 6.9) than MedLift subjects (24.2 ± 4.9). Qmax was also significantly lower in RWR OML subjects than RWR LL and MedLift patients. Following PUL, we report similar absolute IPSS and QoL scores following PUL between RWR OML and RWR LL subjects throughout follow‐up, with significantly better IPSS and QoL at 3 months in the RWR OML cohort (Figure 1). Despite differences in IPSS at baseline between RWR OML and MedLift subjects, follow‐up absolute IPSS scores were equivalent at each timepoint between both groups (Figure 1). QoL, Qmax, and PVR in RWR OML subjects were similar to or better than RWR LL subjects throughout follow‐up. The rate of post‐procedure catheterization in RWR OML (7.9%) subjects was no different from RWR LL subjects (5.8%) when catheterization was not the standard of care. No difference was seen in all AE rate or rate of specific AEs between RWR OML and LL subjects.

Conclusions: The large multicenter real‐world study of PUL reveals OML subjects exhibit similar symptom response and safety profile compared with LL patients and confirm results from the controlled MedLift study.

MP03-06 The UroLift^® Implant Long‐Term Biological Mechanism Behind Relief from Prostatic Obstruction

CG Roehrborn, P Chin, H Woo

UT Southwestern

Introduction & Objective: The prostatic urethral lift (PUL) using UroLift^® implants has been shown to widen the prostatic urethra, providing safe and effective relief from LUTS in BPH patients. Here, we utilize histological data from pre‐clinical canine tissue, resected tissue from human subjects treated with the UroLift System, and post‐market surveillance data to elucidate the long‐term biological mechanism of action of the UroLift implant.

Methods: Cystoscopy and subsequent histology was analyzed from 4 human PUL patients ‐ cystoscopy at 6‐27 months post‐procedure and tissue resection/histology at 13‐43 months. PUL was performed on 24 dogs and histopathology conducted on surrounding prostatic tissue at 1, 3, 6 and 12 months after implantation. Worldwide post‐market data were reviewed for implant migration, encrustation, and breakage from April 2018 to September 2020.

Results: Clinical cystoscopy of human PUL subjects reveals that UroLift^® implants maintain compression of the urothelium, which results in widening of the urethra and retracted lobes. Canine histopathology demonstrate tissue compression occurring immediately, paired with locally decreased blood flow which is followed by benign lobular atrophy by 1 and 6 months (Fig 1). Human histopathology reveals a similar process. Minimal‐mild chronic inflammation was observed at the implant‐tissue interface at 1‐month post‐implantation. At 6 and 12 months post‐implantation, signs of a stable and normal healing response were observed with minimal chronic inflammation and minimal‐mild fibrosis. Increased lobular atrophy and scarring occur through 12 months post‐implantation, and the implant may become fully encapsulated within prostatic tissue by 6 months. Post‐market data from over 770,000 implants did not demonstrate evidence of migration after a successful deployment, and revealed a 0.006% rate of stone formation from encrustation and a 0.004% breakage rate.

Conclusions: The UroLift implants immediately provide localized compression and induces chronic tissue remodeling through 12 months. When implants are placed properly, these changes occur safely and with minimal risk of migration, encrustation, or breakage, affirming the benign nature of this non‐thermal approach.

MP03-07 Aquablation Outcomes in Superlarge Prostates

A Kasraeian, M Alcantara, K Mola Alcantara, S Sterious, N Patel, R Gonzalez, D Elterman, B Helfand, B Chughtai, L Kriteman, A Te

Kasraeian Urology

Introduction & Objective: To determine if Aquablation can safely and effectively treat prostates that exceed 150cc in size (defined as superlarge) in men suffering from lower urinary tract symptoms (LUTS) due to benign prostatic hyperplasia (BPH). The most commonly performed procedure in this prostate size category would be a simple prostatectomy that is associated with severe bleeding complications ranging from 12% to 29%(1).

Methods: Data from Aquablation procedures from surgeons who had performed multiple procedures on superlarge prostates since 2018 in North America was collected and analyzed. A retrospective analysis was performed on procedural details and short term clinical outcomes.

Results: Seventy‐eight (78) Aquablation cases were performed on men with prostates meeting the definition of superlarge with a mean prostate size of 195cc (range 150 to 363cc) across eight hospitals and 18 surgeons. The average number of Aquablation treatment passes was 2.3 (range 1 to 5). Fifty‐five (55%) of patients were done under spinal anesthesia. Postoperative bleeding requiring transfusion occurred in three cases and no take‐back for fulguration was noted in this cohort.

Conclusions: Aquablation performed in superlarge prostates has demonstrated a similar procedural safety profile as reported in previous Aquablation clinical trials (WATER, WATER II, and OPEN WATER).

References

1. Pariser JJ, Pearce SM, Patel SG, Bales GT. National Trends of Simple Prostatectomy for Benign Prostatic Hyperplasia With an Analysis of Risk Factors for Adverse Perioperative Outcomes. Urology. 2015 Oct 1;86(4):721–6.

MP03-08 Post‐operative pelvic pain after prostate enlargement transurethral procedures: A systematic review and meta‐analysis.

ML Wroclawski, D Castellani, F Heldwein, SB Teles, JD Cha, H Zhao, T Herrmann, V Vinson, J Teoh

School of Medicine, Faculty of Medicine and Health, University of Leeds, Leeds Department of Targeted Intervention, Division of Surgery and Interventional Science, University College London, London

Introduction & Objective: We performed a systematic review and meta‐analysis to evaluate and compare the incidences of post‐operative pelvic pain in patients undergoing ablation, enucleation and conventional transurethral resection of the prostate (TURP).

Methods: A systematic review and meta‐analysis was conducted according to the PRISMA guidelines. Using MEDLINE via PubMed and Cochrane CENTRAL, randomised control trials (RCTs) and observational studies reporting dysuria rates post‐ablation, enucleation or TURP were identified using relevant keywords. The risk of biases in included comparative RCTs and observation studies were assessed using the Cochrane Risk of Bias tool and the Newcastle‐Ottawa Scale respectively.

Results: 62 studies were included for qualitative analysis, while 51 of them reported number of patients with dysuria post‐intervention. Three observational studies and 13 RCTs compared the rates of dysuria in patients undergoing ablation, enucleation or TURP. The pooled incidence of dysuria in patients undergoing ablation, enucleation and TURP were 0.15 (95% CI 0.10 – 0.22), 0.01 (95% CI 0.00‐0.03) and 0.10 (95% CI 0.06‐0.15) respectively. Upon comparison of the three interventions, ablation is associated with a higher risk of dysuria than enucleation (RR 2.19, 95% CI 1.04‐4.62) and TURP (RR 2.40, 95% CI 1.03 – 5.62) in observational studies but not RCTs; and there were no significant differences in the rates of dysuria in the other comparisons.

Conclusions: Persistent dysuria is relatively common after transurethral benign prostatic hyperplasia surgery. Patients undergoing ablation had a higher rate of post‐intervention dysuria than those undergoing enucleation and TURP in observational studies. It is important to counsel our patients on the possibility of prolonged dysuria after surgery.

MP03-09 WATER vs WATER II: Three Year Comparison of Aquablation Therapy for Benign Prostatic Hyperplasia

D Nguyen, KC Zorn, N Bhojani

University of Montreal Hospital Center (CHUM)

Introduction & Objective: Surgical options are limited when treating large (>80cc) prostates for lower urinary tract symptoms (LUTS) due to benign prostatic hyperplasia (BPH). Open simple prostatectomy remains the most common procedure performed for large prostates. As such, there is a need for novel surgical approaches with shorter learning curves and effective treatment. Aquablation (AquaBeam System, PROCEPT BioRobotics, Inc., USA), an ultrasound‐guided, robotically executed waterjet ablative procedure, could fill this gap. This analysis compares the outcomes of Aquablation in 30cc to 80cc prostates with the outcomes in 80cc to 150cc prostates.

Methods: WATER (NCT02505919) is a prospective, double‐blind, multicenter, international clinical trial comparing the safety and efficacy of Aquablation and TURP in the treatment of LUTS/BPH in men 45 to 80 years old with a prostate between 30cc and 80cc. WATER II (NCT03123250) is a prospective, multicenter, single‐arm international clinical trial of Aquablation in men with a prostate between 80cc and 150cc. We compare 36‐month outcomes amongst 116 WATER and 101 WATER II study subjects undergoing Aquablation. Students' t‐test or Wilcoxon tests were used for continuous variables and Fisher's test for binary variables.

Results: International Prostate Symptom Score (IPSS) scores improved from 22.9 and 23.2 at baseline in WATER and WATER II, respectively, to 8.0 and 6.4 at 36 months, with 36‐month reductions of 14.4 and 16.7 points, respectively (p = .07 for difference in change scores). At baseline, urinary flow rate (Qmax) was 9.4 and 8.7 cc/sec in WATER and WATER II, improving to 20.6 and 19.0 cc/sec, respectively (p = .70 for difference in change scores) at 36 months. Improvements in both IPSS and Qmax were immediate and sustained throughout follow‐up. Change in IPSS, Qmax, and post‐void residual (PVR) can be found in Figure 1.

Conclusions: Aquablation clinically normalizes outcomes between patients with a 30cc to 80cc prostate and patients with an 80cc to 150cc prostate treated for LUTS/BPH. It is effective in patients with large prostate glands (>80cc) with acceptable complications out to three years.

MP03-10 Withdrawn

MP03-11 Withdrawn

MP03-12 Prostatic Urethral Lift ‐ Influence of advanced techniques on benign prostatic enlargement patient pathway

A Dhanasekaran

Sandwell And West Birmingham NHS Trust

Introduction & Objective: Prostatic urethral lift (PUL) is an approved minimally invasive surgical procedure to relieve voiding urinary symptoms associated with a benign prostatic enlargement (BPE). It is a day‐case procedure, recommended by the United Kingdom National Institute for Health and Care Excellence (NICE). Advanced techniques to treat men with Obstructing Median Lobe (OML) and high bladder neck have been developed. This study assessed whether using advanced techniques and a modified, simplified patient pathway could shorten and improve the patient pathway, thereby helping to reduce waiting time and overall cost.

Methods: Eligible patients were men who were referred to hospital for BPE treatment. Group A followed the traditional BPE pathway (clinic assessment, prostate volume and flexible cystoscopy, flow rate and bladder scan, surgery under general anaesthesia, and clinic‐based outpatient follow‐up). Group B followed a simplified pathway, using advanced techniques, involving clinical assessment, flow rate and bladder scan, PUL under local anaesthetic, and telephone follow‐up. Differences in time to PUL, quality of recovery visual analogue scale (QoR‐VAS) and pelvic pain tolerability visual analogue scale scores (VAS), International Prostate Symptom Scores (IPSS), quality of life (QoL), and overall costs were compared between groups.

Results: In the last twelve months from March 2019 to February 2020, 24 patients were treated in group A and 15 in group B (average prostate size: 84g and 79g respectively). The simplified pathway was associated with shorter waiting times for PUL than the traditional pathway. Similar mean outcomes 3 months after PUL were seen for QoR‐VAS (group A 89% vs. group B 87%), IPSS, QoL, and pain tolerability score (Table 1). The number of implants between group A and group B was also comparable; 2.8 ± 0.9 (range: 2‐4) and 3.2 ± 1.0 (range: 2‐5) respectively. Overall expenditure was reduced in group B due to less need for preoperative investigations and telephone follow‐up.

Conclusions: Outcomes were not affected by fewer preoperative investigations. Our findings support using PUL to treat a broadened group of men with obstructive urinary symptoms from BPE (including men with OML and high bladder neck) in an ambulatory setting via a simplified pathway.

The major new findings of the study ‐ New advanced techniques in PUL simplify BPE pathway and offer excellent results.

MP03-13 Prognostic factors predicting late bleeding after ThuLEP

M Maltagliati, L Berti, U Besana, A Calori, C Buizza, BC Rocco, S Micali, M Sighinolfi, G Bozzini

ASST Valle Olona

Introduction & Objective: To evaluate late bleeding risk and its predicting factors in patients operated for benign prostatic obstruction with Thulim Laser Enucleation of the Prostate (ThuLEP).

Methods: Patients operated with ThuLEP between 2015 and 2018, in three departments of Urology were included. Each patients had an indication to ThuLEP acording to EAU guidelines. Each of them was controlled for the first month and re‐admitted if a late post‐operative hematuria showed off. A monovariate and a multivariate analysis was conducted to understand if any of the following conditions would have lead to an encreasing risk of bleeding after hospitalization: Age, BMI, Prostate size bigger than 150 ml, Hypertension, non insulin‐depndent diabets mellitus (NIDDM), history of constipation, anticoagulants therapy (early or late bridging), antiaggregant therapy, previous transfusion, ASA status, previous urinary catheter.

Results: 748 patients were included in this study, 52 (6.9%) of them were re‐admitted after the discharge because of gross hematuria (with or without cloths retention). Mean duration of the first hospitalization was 2.1 days while the the mean duration of the re‐admission was 5.6 days. No on of the re‐admitted patiens required a re‐intervention while 46.1% of them had blood transfusion.

We found a statistical significance difference in patient re‐admitted for hematuria if they had NIDDM as a comorbidity (p < 0.05), had a late (i.e. at home and not during hospitalization) bridging of their oral anticoagulant drug with low molecular weight eparin (p < 0.05) and had a clinical history of constipation (p < 0.05).

Conclusions: Bleeding risk of BPO surgery using ThuLEP is less then in other procedures but it is still a concern. Patient with clinical history of NIDDM, constipation and who had a late bridging of their oral anticoagulant therapy are in risk for a late bleeding after ThuLEP.

MP03-14 Post Enucleation Morcellation procedure: Lights and Shadows

L Berti, M Maltagliati, P Marcangeli, A Calori, U Besana, C Buizza, M Sighinolfi, S Micali, BC Rocco, G Bozzini

ASST Valle Olona

Introduction & Objective: To compare clinical intra and early postoperative outcomes after Endoscopic Enucleation of the Prostate (EEP) with different morcellators to treat benign prostatic hyperplasia (BPH).

Methods: This prospective randomized study enrolled consecutive patients with BPH to be treated with EEP (Holep, ThuLEP, ES ThuLEP, VB HoLEP). Three different morcellators where randomizly used thus to divide pts into 3 groups. A for Wolf Piranha, B for Storz drllcut and C for Quanta Cyber Blade. All patients were evaluated preoperatively with regards to blood loss, complications, catheterization time, irrigation volume, hospital stay and operative time.

Results: 312 patients were enrolled. 103 in group A, 107 in B and 102 in C. Patients in each study arm each showed no significant difference in preoperative parameters with main regard to prostatic volume. Compared with A, and B group C had faster operative time (42.54 ± 31.55 minutes, P = 0.04) but not resulted in a less hemoglobin decrease (A vs C and B vs C, p = 0.31 and p = 0.28). The same happened to complication rate which is mostly related to bladder injury morcellation‐related and reflected an higher catheterization time and hospital stay. Despite this Quanta Morcellator had an higher cost per procedure. During the 12 months of follow‐up, the procedures did not demonstrate a significant difference in Qmax, IPSS, PVR, and QOLS.

Conclusions: All the morcellators tested equally allowed a good procedure with and higher efficacy in terms of time for the Quanta which (due to its disposable nature) exposed to higher costs per procedure. Complications are mainly related to operator skill in morcellation procedure than to the device used.

MP03-15 The Gold Standard Technique for Robotic‐Assisted Simple Prostatectomy: A Multi‐Institutional Assessment of Postoperative Urinary Function Outcomes

CU Okoro, M Lee, JY Lee, S Shekar, G Reyes, M Loecher, N Krishnan, AC Harbin, DD Eun

Department of Urology, Lewis Katz School of Medicine at Temple University

Introduction & Objective: Robotic‐assisted simple prostatectomy (RASP) has been readily adopted by robotic surgeons for management of patients with refractory lower urinary tract symptoms (LUTS) and large prostate glands. We assess the degree and durability of postoperative urinary function improvement in patients who underwent RASP using a transvesical technique with a 360° circumferential urethrovesical anastomosis.

Methods: We retrospectively reviewed a multi‐institutional series of patients who underwent RASP by two separate surgeons utilizing a similar technique. The indication for surgery was bothersome LUTS or urinary retention refractory to medical management. The severity of LUTS was assessed using the International Prostate Symptom Score (IPSS) and quality of life (QOL) score. Urinary function outcomes were assessed at 2 weeks, 3 months, 6 months, 9 months, 12 months, 18 months, 24 months and greater than 24 months postoperatively.

Results: A total of 520 patients were identified between May, 2013 and February, 2021. Patient demographics and perioperative outcomes are outlined in Table 1. Mean IPSS and QOL scores improved between 2 weeks and 6 months, with durable results at follow intervals greater than 24 months (Figure 1). Postoperative complications (Clavien Grade >2) were noted in 4.2 % (22/520) of patients. Three patients (0.6%) developed postoperative de‐novo stress urinary incontinence and no patient developed a bladder neck contracture. One patient required reoperation for LUTS.

Conclusions: Robotic‐assisted simple prostatectomy is a safe and effective option for patient with refractory LUTS. Given the durable urinary functional outcomes and minimal complications, we propose this our technique be adopted as the gold standard for RASP.

MP03-16 Outcomes and Complications of bipolar enucleation by prostate size

JN Warner

City of Hope

Introduction & Objective: Bipolar enucleation of the prostate (BipoLEP) is an alternative to holmium laser enucleation of the prostate. Whether pre‐operative prostate size affects BipoLEP outcomes remains unclear.

Methods: We retrospectively reviewed a prospectively collected single‐institutional database of BipoLEPs. We collected demographics, peri‐operative details, complications and patient‐reported outcomes at 6 weeks, 4 months and 1 year post‐operatively.

Results: From 9/2015‐11/2020, 310 patients underwent BipoLEP; 296 had accurate volume data and minimum 4‐month follow‐up. Median pre‐operative prostate volume was 74.5g (range 17‐360g). Patients were analyzed by large (>75g n = 148) versus small (< 75g n = 148) volume. Larger volume patients were older (72 vs. 69; p < 0.05) and were more likely to be in retention (37% vs. 25%; p < 0.05). Patient reported outcomes are detailed in Figure 1. Patients reported similar rates of stress incontinence (any degree) at 4 months (20% large vs. 14% small, p = 0.21). Only 3 patients (2 large, 1 small) requested anti‐incontinence interventions at 1‐year. Bladder neck contracture occurred exclusively in patients with smaller prostates (n = 16, 11%); small volume patients also had more urethral strictures (7% vs. 1%, p < 0.05)

Conclusions: Following BipoLEP, patients with small prostates have higher rates of bladder neck contractures and urethral strictures along with worse IPSS scores and BI's at all time points. Alternative modalities may be considered for smaller glands.

MP03-17 Outcomes Following Surgical Treatment of BPH in Patients with Neurologic Diseases

M Wahba, J Vetter, A Paradis, C Nottingham

Washington University School of Medicine

Introduction & Objective: Clinical outcomes after treatment of Benign Prostatic Hyperplasia (BPH) are poorly defined in patients with neurologic deficits. The efficacy of treatments for BPH may be impacted by presence of comorbid detrusor underactivity in these patients, and the potential for complications such as incontinence may be a deterrent for surgery. We set out to define clinical outcomes for patients with neurologic deficits undergoing BPH treatment.

Methods: We conducted a retrospective review at a tertiary care center of patients with neurologic diseases undergoing surgical treatment of BPH surgery with either laser vaporization or transurethral resection of the prostate. We included patients with a chart diagnosis of cerebrovascular accident, spinal cord injury, myasthenia gravis, and Parkinson's from 2017 through 2019. We performed chi‐squared analysis to compare voiding dysfunction, use of medication, complications, and AUA symptom questionnaires before and after treatment of BPH.

Results: We included 30 patients with a mean follow‐up of 5.7 months. Urinary retention rates (48.3% vs 16.7%, p = 0.009) and use of alpha‐blocker medications (66.7% vs 26.7%, p = 0.002) were significantly lower after surgical treatment. The median American Urological Association (AUA) symptom score decreased from 23 to 19 post‐operatively (p = 0.317), with half of patients experiencing an increase in their score. There was no impact of surgical treatment on infection rates, incontinence, or use of other medications.

Conclusions: Patients with neurologic disorders who underwent treatment of BPH had improvements in urinary retention and use of alpha‐blocker medications. However, there was no significant change in AUA symptom score. Larger studies are needed to determine which patients among this population may derive the most benefit or harm from surgical intervention.

MP03-18 Identifying Predictors of Antispasmodic use Following Robotic Assisted Simple Prostatectomy

JC Dai, TN Morgan, A Garbens, S Kusin, H Trivedi, H Kominsky, CG Roehrborn, JC Gahan

UT Southwestern

Introduction & Objective: Predictors of anticholinergic or beta‐3 agonist use following robotic simple prostatectomy (RASP) are not well established. We describe the rate of anti‐spasmodic use following RASP and identify potential predictors of medication use to better counsel patients pre‐operatively.

Methods: A retrospective review of all RASP patients from 2/2016 ‐ 1/2020 was conducted. Patients with no pre‐operative International Prostate Symptom Score (IPSS) were excluded. Demographic data and pre‐operative clinical characteristics were collected. Post‐operative medication use was determined through electronic medical record review, with at least 1 week of utilization required. Multivariable logistic regression analysis using a priori determined variables was performed to identify independent factors associated with anti‐spasmodic use.

Results: 255 patients underwent RASP at a mean age of 70.0 years ±7.3 and mean BMI of 28.6 kg/cm ±5.0. Median pre‐operative prostate volume was 132.3 cc ±45.0. Rates of pre‐operative diabetes, obstructive sleep apnea (OSA), smoking and alcohol use (≥7 drinks/week) were 19.6%, 6.3%, 3.1%, and 11.8% respectively. Mean pre‐operative IPSS and quality of life scores were 17.6 ± 7.8 and 3.6 ± 1.6, respectively. Median pre‐operative post‐void residual and Qmax were 118 cc (IQR 61‐225) and 8.3 cc/sec (IQR 6.2‐11.8), respectively. 8.6% of patients (n = 22) initiated anti‐spasmodics post‐operatively at a median time of 2.5 months (IQR 1.3‐4.2). These patients were more likely to have a history of OSA than the remainder of the cohort (22.7% vs 5%, p = 0.007). Median duration of anti‐spasmodic use was 6.5 months (IQR 1.7‐14.7). Mirabegron was the most commonly used medication (31.8%). On multivariable logistic regression analysis including history of smoking, diabetes, OSA, alcohol use, BMI, and pre‐operative IPSS score, OSA was independently associated with post‐operative anti‐spasmodic use (OR 8.5, 95% CI 2.12‐34.2, p = 0.003). 68.8% of OSA patients were treated with continuous positive airway pressure (CPAP), but treatment did not appear to impact post‐operative anti‐spasmodic use.

Conclusions: Rates of new anti‐spasmodic use following RASP are comparable to those following other bladder outlet procedures. Patients who are diagnosed with OSA are almost 9 times more likely to require anti‐spasmodic medications following RASP in the short term. These patients may benefit from more tailored pre‐operative counseling.

MP03-19 Surgical Treatment of Large Gland BPH : A Comparison Between ThuLEP and Single Port Transvesical Robotic Simple Prostatectomy

S Talamini, HT Vigneswaran, MJ Zuberek, S Crivellaro

University of Illinois at Chicago

Introduction & Objective: The surgical management of large gland benign prostatic hyperplasia (BPH) can pose significant challenges. In the large gland, guidelines suggest the use of innovative approaches including endoscopic enucleation and robotic simple prostatectomy, traditionally performed using a multiport platform. The daVinci Single Port robot offers a less invasive approach to the simple prostatectomy. We compare our experience using Thulium laser enucleation of prostate (ThuLEP) to the Single Port robotic assisted simple prostatectomy (SP RASP).

Methods: A retrospective review was conducted from 2019 to 2021 of men that underwent SP RASP and ThuLEPs performed by a single surgeon with an enucleation experience of >300 cases. We evaluated preoperative factors such as age, BMI, preoperative prostate medications, IPSS scores, and post void residual(PVR); perioperative measures including operative time, and dry weight of the specimen were recorded; postoperative outcomes including complications, length of foley catheter, IPSS score, urinary incontinence and PVR were recorded. When comparing SP RASP and ThuLEPs, continuous variables were compared using Kruskal Wallace tests. Categorical variables were compared using chi squared tests with two sided p‐values.

Results: In total 16 SP RASPs and 41 ThuLEPs were performed. Median age was 68 years (IQR: 63 – 73), median BMI was 28 (25 – 31), median preoperative PSA was 7.2 ng/mL (IQR: 2.8 – 12.4) and median follow up was 3 months (IQR: 1.3 – 7.0). ThuLEP had shorter operative times (min) (100 vs 175, p < 0.001), smaller specimen weight (g) (46.5 v 80, p = 0.027), and shorter postoperative catheter time (d) (3 vs 7, p < 0.001). SP RASP was associated with fewer postoperative complications such as dysuria, hematuria requiring CBI, and UTI. IPSS reduction was similar between the two procedures. Incontinence rates were less with SP RASP as compared to ThuLEP (5.6% vs 7.3%, p = 0.002). Same day discharge was higher in the ThuLEP group (78% vs 43%).

Conclusions: ThuLEP is associated with shorter postoperative catheter days, decreased operative times, and decreased length of stay (LOS), likely confounded by the initial cases performed on the SP platform, who tended to have longer hospital stays. Subsequent cases have trended towards same day discharge. SP RASP demonstrates improved continence rates, likely a consequence of the bladder neck reconstruction. Though SP RASP is within the initial learning curve at our institution, early results demonstrate the role for this modality alongside ThuLEP in the treatment of large gland BPH.

MP03-20 Pivotal roles of macrophage recruitment and polarization in bladder outlet obstruction

W Wang, K Xiao, H Chen, L Zhou

Introduction & Objective: Partial bladder outlet obstruction (pBOO) is a ubiquitous problem in urology, and lead to significant morbidity in the population. It is characterized by an initial inflammatory response, smooth muscle hypertrophy, exaggerated extracellular matrix accumulation and eventual decompensation to fibrosis. The development of pBOO involve a series of cells and are modulated by complicated molecular networks. Macrophages, the most plastic cells of the hematopoietic system, regulate immunity and are pivotal for tissue repairment. However, the relationship between macrophage and pBOO remains unclear. We established an experimental pBOO rat model to investigate the role of macrophage during pBOO progression.

Methods: Heathy, adult, Sprague Dawley rats underwent surgical creation of a pBOO for either 1, 3, 6 weeks and were compared with sham‐operated rats. Bladder tissue was collected for flow cytometry, quantitative reverse transcription polymerase chain reaction, histology examinations, immunostaining and immunofluorescence assay.

Results: The polarization of bladder macrophages was dysregulated during pBOO development. In the initial stage of pBOO, M1 macrophages were induced and played a leading role (M1/M2 > 4) in eliciting inflammatory.; in the late stage, M2 macrophages were induced (M1/M2 < 0.5) to promote tissue fibrosis. Moreover, our results showed a direct pro‐fibrotic role for M2 macrophage via transition into myofibroblast in a process termed macrophage‐myofibroblast transition (MMT). Co‐expression of M2 macrophages (CD163), myofibroblast antigens α‐smooth muscle actin (α‐SMA) and collagen I identifies the MMT process in the development of pBOO. The number of MMT cells increased with the development of PBOO and accounting for more than 60% of α‐SMA⁺ collagen‐producing myofibroblasts. Additionally, levels of several cytokines in bladder tissue microenvironment changed with macrophages polarization. Inflammatory cytokines such as monocyte chemoattractant protein‐1, chemokine (C‐C motif) ligand 5 (CCL5), and interleukin (IL)‐1β were significantly increased in the inflammation stage compared with sham group (p < 0.05); While collagen I, collagen III, fibronectin, matrix metalloproteinases (MMP)‐2, tissue inhibitor of matrix metalloproteinase 2 (TIMP‐2) and TIMP‐1 were upregulated in the fibrosis stage compared with sham group (p < 0.05).

Conclusions: In summary, macrophages play a pivotal role in the development of pBOO and might be a key point for elucidating pBOO pathogenesis.

MP03-21 Minimally Invasive Surgical Treatment of Benign Prostatic Hyperplasia: A Systematic Review

A Ting, N Shanmugathas, C Khoo, T El‐Husseiny, H Abboudi

Imperial College Healthcare NHS Trust

Introduction & Objective: Minimally invasive surgical treatments (MISTs) of benign prostatic hyperplasia (BPH) have evolved to offer men daycase care with preservation of urinary continence and sexual function. This systematic review evaluates trends in minimally invasive BPH surgery over the last decade.

Methods: Systematic review (PRISMA) of Embase/MEDLINE databases (2010‐2020). MISTs included Rezum, Urolift, Prostatic Artery Embolisation (PAE), Temporary Implantable Nitinol Device (TIND), Intraprostatic Injection (II), Transurethral Microwave Therapy (TUMT) and Transurethral Needle Ablation (TUNA). The primary outcome was change in urinary function (International Prostate Symptom Score (IPSS)/IPSS‐Quality of Life (IPSS‐QoL)/maximum flow (Qmax)). Secondary outcomes included change in sexual function (International Index of Erectile Function‐5 (IIEF5)), technical failures and complications. Risk of bias was assessed using Cochrane RoB 2.0/MINORS (for randomised/non‐randomised studies, respectively).

Results: 74 studies were included (total: 8,917 patients). The most studied intervention was PAE (36 studies). All interventions offered improvement in urinary function at various points of follow‐up. PAE achieved the greatest improvement in IPSS, IPSS‐QoL and QMax, but also had the largest range of results in every domain. 6 studies reported outcomes ≥48 months (PAE: 2; Rezum, Urolift, TUMT, TUNA: 1); improvements in urinary function were sustained in all. 33 studies across all interventions except TIND and TUMT reported IIEF5 change‐ sexual function was largely preserved (figure 1). Technical failures and Clavien‐Dindo ≥3 complications were rare. Overall, risk of bias was low.

Conclusions: MISTs for BPH are effective and safe. However, there is high clinical heterogeneity within the existing literature. Randomised multi‐arm comparative studies with long‐term urinary and sexual follow‐up are needed to help inform choice. Until then, patients should be carefully counselled based on individual priorities and circumstances.

MP03-22 Minimally Invasive and Endoscopic Therapies of Benign Prostatic Hyperplasia (BPH): Head‐to‐Head Comparison of Short‐Term outcomes by Multiple Treatments (Network) Meta‐Analysis

L Hamed, E Olweny

Rush University Medical Center

Introduction & Objective: There has been a recent explosion in the number of endoscopic and minimally invasive surgical therapies for the treatment of lower urinary tract symptoms related to BPH (LUTS/BPH), with an associated increase in the volume of BPH surgery. However, outcomes for the available BPH surgeries have not previously been compared in head‐to‐head fashion, and we sought to do so using network meta‐analysis.

Methods: We systematically reviewed randomized controlled trials from 1998 to 2018 reporting BPH surgical outcomes in men with moderate‐severe LUTS based on International Prostate Symptom Score (IPSS), maximum urinary flow rates (Qmax) of <15 mL/s and prostate sizes <100 g. Subjects received any of 10 different treatments, i.e. mono‐ or bipolar transurethral resection of the prostate (mTURP, bTURP), aquablation, vaporization, enucleation, transurethral microwave thermotherapy (TUMT), transurethral needle ablation (TUNA), water vapor thermotherapy (Rezum), prostatic urethral lift (PUL) or sham. The primary outcomes were IPSS, quality of life (QOL), Qmax and international index of erectile function (IIEF) scores at 1 year. Multivariable random effects network meta‐analysis was used to compare the treatments using direct and indirect evidence. For each outcome, treatments were ranked from best to worst using the surface under the cumulative ranking curve (SUCRA) method (higher SUCRA = better treatment). Referent treatment was mTURP.

Results: A total of 26 studies with 3,950 patients met inclusion criteria. Relative to mTURP, 1‐year mean IPSS and QOL scores were statistically similar for all treatments except sham, which had a worse QOL score. Mean Qmax was similar for all treatments except TUNA, Rezum, PUL and sham, which had significantly lower flow rates. IIEF data were available for only 7 of the treatments, with mean scores for vaporization, Rezum, PUL and sham significantly better than for mTURP, while those for enucleation and bTURP were similar (Figure). By SUCRA, the treatment with the highest probability of best urinary function was enucleation, while that with the highest probability of best sexual function was Rezum.

Conclusions: Compared with mTURP, Rezum and PUL achieved inferior flow rates but better IIEF scores, while vaporization achieved similar flow rates and higher IIEF scores. These findings may be of value in patient counseling regarding surgical outcomes of LUTS/BPH therapy.

MP04-01 Withdrawn

MP04-02 First comminution of stones in humans by burst wave lithotripsy

JD Harper, JE Lingeman, I Metzler, RM Sweet, P Sunaryo, JC Williams, AD Maxwell, J Thiel, B Cunitz, B Dunmire, MR Bailey, M Sorensen

University of Washington School of Medicine

Introduction & Objective: We report stone comminution in the first human subjects by burst wave lithotripsy (BWL), which is the transcutaneous application of focused, cyclic ultrasound pulses.

Methods: This is a prospective multi‐institutional feasibility study recruiting subjects undergoing clinical ureteroscopy (URS) for at least one stone ≤12 mm on computed tomography (CT). During the planned URS, BWL is administered with a handheld probe, and any stone fragmentation and tissue injury are observed. Up to 3 stones can be treated, each for a maximum of 10 min to be respectful of operating room time. The primary effectiveness outcome is the volume percent comminution into fragments ≤2 mm, where fragment volume is determined by μCT of basketed fragments or image processing of the URS video using the laser fiber as a size reference. The primary safety outcome is independent, blinded grading of tissue injury from the video.

Results: Comminution data to date are from 6 female and 6 male subjects with an average BMI of 25 ± 5 kg/m2 and average age of 57 ± 15 years. Overall, 13 of 15 stones were comminuted with BWL (Table 1). In 8 of 15 cases, ≥85% of the stone was comminuted to fragments ≤2 mm in under 10 min. One stone in the distal ureter was 87% comminuted after 4 min before passing into the bladder. Seven stones were <85% comminuted, potentially because of their size ( > the beam width or < the acoustic wavelength), composition, structure, or the introduction of air by URS that shielded the stone from BWL. Figure 1 shows fragments from the 20% comminuted stone and tissue around the 99% comminuted stone. Only mild reddening with some hematuria was observed ureteroscopically.

Included in the tissue observations were 2 additional BWL‐treated subjects where the stone identified on CT was determined to be most likely submucosal on URS. For another additional BWL‐treated subject, fragments were noted, but the URS video did not record for comminution or tissue measurement.

Conclusions: The first study of BWL in human subjects resulted in an average of 63% comminution of stones into fragments ≤2 mm within a treatment time of only 10 min and with only mild tissue injury.

MP04-03 Comparison of Laparoscopic Pyelolithotomy versus Percutaneous Nephrolithotomy for the Treatment of patients with Staghorn Kidney Stones referred to Labbafinezhad hospital in 2019; a randomized clinical trial

M Soltani, S Farshid, R Valizadeh, N ahmadian

Introduction & Objective: Percutaneous nephrolithotomy is a standard treatment for Staghorn kidney stones but due to parenchymal damage and the possibility of pseudoaneurysms and severe hemorrhage, selective alternative to low invasive alternative such as laparoscopy was considered to compare therapeutic results and complications with percutaneous nephrolithotomy.

Methods: This study was a parallel randomized clinical trial study. 68 Patients with Staghorn stones (one‐piece or maximally two‐pieces stones with large extra renal part) over 18 years were Included in this study. The patients were randomly divided into two equal groups of laparoscopic Pyelolithotomy and PCNL using random allocation software. The primary outcome was the success rate of stone free rate, And Secondary outcomes were pre‐operative creatinine, post‐operative creatinine, duration of surgery, bleeding, fever, post‐operative pain, length of hospital stay, pre‐operative hemoglobin and post‐operative hemoglobin. Independent t‐test or Mann‐Whitney test were used to compare quantitative variables between the two groups.

Results: The mean age of patients in PCNL and laparoscopic Pyelolithotomy groups was 48.50 ± 13.33 years and 52.17 ± 15.74 years, respectively (p = 0.303). Laparoscopic Pyelolithotomy strongly had longer surgery time (196.55 ± 26.58 minutes) than PCNL group (110.88 ± 34.82 minutes) (t = ‐11.404, p = 0.001). Regarding high grade clavien complications( III‐V), the results showed no significant differences between two groups . Regarding hemoglobin decrease, the patients in the PCNL group showed more Hb decrease (‐2.6676 ± 2.61 g/dl) compared to the Laparoscopic Pyelolithotomy (‐0.7912 ± 1.06 g/dl) (t = ‐3.852, p = 0.001). )Stone free rate was observed in 76.5% (n = 26) of patients in laparoscopic Pyelolithotomy group, which was significantly higher than the PCNL group (n = 17) (p = 0.043).

Conclusions: Given that during the laparoscopy the entire pyelocalyceal system is accessible, it is possible to remove the stone completely, but in PCNL surgery it may require multiple accesses to remove the stone in a single session. Also, according to the results, laparoscopic Pyelolithotomy had more stone free rate accompanied with low hemorrhage requiring transfusion compared to PCNL procedure for single piece staghorn stones with large extra renal part.

MP04-04 Complications after 4,500 flexible ureteroscopy (academic single center experience)

BF Geavlete, R Multescu, C Ene, C Bulai, PA Geavlete

“Saint John” Emergency Clinical Hospital, Department of Urology

Introduction & Objective: Nowadays flexible ureteroscopy became a routine procedure utilized all‐around of the world. The aim of this study was to evaluate the indications, limits and efficacy of flexible ureteroscopy on a significant number of cases and on a long follow‐up period.

Methods: The procedures were performed by three surgeons, between January 2003 – January 2019 and involved 7 types of flexible ureteroscopes: Storz 11274AA, Storx Flex‐X, Storx Flex‐Xc, Storz Flex‐Xc2, Olympus URF‐P5, Olympus URF‐V, Olympus URF‐V23000. We retrospectively reviewed the indications, endoscopes' types, procedural efficacity and complications rates.

Results: Overall complications occurred in 18.9% of the procedures. Septic complications (ranging from fever to septic shock) occurred in 12.1% of the cases, most of them being mild. In this complications category, 69% were Clavien II, 16% Clavien IIa, 10% Clavien IVa and 5% Clavien IVb. Mortality was 0% in this group. 51.9% of the septic patients were pre‐stented, and only 25% of them were operated using a ureteral access sheath. In 6.8% of the cases non‐septic complications (severe upper urinary tract wall lesions, postoperative pain, persistent hematuria, liquid retroperitoneal extravasation, intrarenal or subcapsular hematoma) were encountered. No Clavien V cases were encountered in this group either. Ureteral access sheath was used in 78% of the non‐septic complications group. During the diagnostic procedures inspection of the entire upper urinary tract was possible in 90% of the cases (2,700 patients). Stone free rate in lithiasis cases was 93.3% after one procedure, 95.2% after the second and 97.3% after the third one. In 22 cases intraparenchimatous (5 cases) or subcapsular hematoma (17 cases) were diagnosed during the postoperative period, while 3 cases presented massive liquid extravasation of the fluid in the retroperitoneum. Regarding the use of ureteral access sheath, in 4.8% of the cases we encountered grade 2 and 3 ureteral wall injuries.

Conclusions: Retrograde flexible ureteroscopic approach is an efficient diagnostic and treatment method for renal pathology. Also the complication rate is relatively reduced, but a serious training is indicated before using this device.

MP04-05 Role of stone size, stone density, and skin‐to‐stone distance by non‐ contrast computed tomography abdomen in predicting success of shock‐wave lithotripsy for kidney stones

A Hamid, A Ahmad, N Choh, S Malik, R Khawaja, M Wani

Department of Urology, SKIMS, Srinagar, Kashmir, India

Introduction & Objective: Shock‐wave lithotripsy (SWL) is a minimally invasive treatment procedure for kidney stones, commonly employed as one of the first line therapy for properly selected renal and ureteric stones. Multiple factors influence the outcome of shock‐wave lithotripsy and assessment of certain CT characteristics of the these stones prior to the procedure can help in predicting outcome of shock‐wave lithotripsy. The aim of this study was to assess the influence of these factors in predicting the outcome of shock‐wave lithotripsy for kidney stones.

Methods: Between March 2016 and June 2018, 96 patients who underwent shock‐wave lithotripsy for renal or proximal ureteric stones at our centre were included in the study. The CT characteristics of the calculi, shock‐wave lithotripsy settings applied, and the final outcome observed were recorded in a proforma and subjected to statistical analysis.

Results: There were 58 (60.42%) males and 38 (39.58 %) females in the study. The age of patients varied from 18 to 72 years with a mean of 36.4 ± 13.8 years. Majority of patients 69 (71.88%) had renal (non‐lower pole) calculi while 27(28.12%) had upper ureteric calculi. Stone size varied from 7.4 mm to 20.0 mm with a mean of 13.1mm ±3.8 mm. The stone density ranged from 536 HU (Hounsfield unit) to 1232 HU with a mean of 826.3 ± 194.3 HU. The mean skin‐to‐stone distance (SSD) varied from 5.58 – 12.5 cm with a mean of 8.84 ± 1.92 cm. Complete stone fragmentation was observed in 65 (67.70%) patients after first session; 16 (16.67%) after second session and 7 (7.30%) after third session. However, 8 (8.33%)patients had failure of shock‐wave lithotripsy and needed alternative treatment. Overall success rate of 91.67% (88/96) was observed. The mean number of shock‐waves required to achieve complete stone fragmentation was observed to increase with the increased stone size and stone density, however, stone density had more significant influence than stone size and mean SSD.

Conclusions: From the study it was concluded that the use of NCCT‐KUB for determining the stone size, stone density, and skin‐to‐stone distance of kidney stones before shock‐wave lithotripsy helps in predicting treatment outcome. The combination of these factors helps to identify ideal candidates for shock‐wave lithotripsy. The increase in mean skin‐to‐stone distance is associated with an increase in the number of shock‐wave lithotripsy sessions required as well as an overall decreased success rate. However stone density appears to be more significant than stone size and skin‐to‐stone distance in predicting fragmentation of kidney stones with shock‐wave lithotripsy.

MP04-06 Upper Urinary Tract Stones: Evolution of Surgical Management Trends in Germany, France and England over the Past Decade

BW Turney, C Demaire, S Klöcker, H Sommerfeld, O Traxer

University of Oxford, Nuffield Department of Surgical Science, Department of Urology, Churchill Hospital

Introduction & Objective: Global Upper Urinary Tract (UUT) stone prevalence is rising. As a consequence, the increased service demand on hospitals may be difficult to manage, increasing the burden on healthcare providers (HCPs) as well as on patients. In this European analysis we explore the evolution of stone diagnoses and surgical procedures in Germany (DE), France (FR), and England (EN) over the past ten years.

Methods: We identified the codes related to UUT stones diagnoses using the International Classification of Diseases (ICD‐10) and extracted procedure counts for Extracorporeal Shock Wave Lithotripsy (ESWL), Ureteroscopy (URS), Percutaneous Nephrolithotomy (PCNL) and Open Surgery (OS). We used procedure codes from the National databases in DE, FR and EN, and analyzed the hospital diagnosis counts versus surgical procedure counts related to UUT stones from 2010 to 2019.

Results: Between 2010‐2019, the ICD‐10 N20 codes for calculus of kidney and ureter increased by 8%; 26% and 15% in DE, FR, EN respectively, whereas stone procedures increased by 3%; 38% and 18%.

Over time the dominant surgical UUT stone procedure shifted from ESWL (49‐60% of all procedures in 2010) to URS (51‐75% of all procedures in 2019). PCNL and OS represent <5% of UUT stones procedures in FR and EN. The highest use of PCNL is observed in DE (increase from 7% in 2010 to 11% in 2019).

Over the past decade, the overall length of stay (LoS) decreased for all procedures across the three countries. The URS average LoS decreased by 21% in DE; 37% in FR and 6% in EN. Daycase stone procedures volume increased in FR by 68% and in EN by 23%. In DE most cases involve at least one overnight stay.

Conclusions: This analysis confirms the rise in stone prevalence globally, including an increase in UUT stones diagnoses and surgical procedures in DE, FR, EN over the past decade.

The dominant surgical procedure to treat UUT stone has shifted from ESWL to URS, and the average LoS has decreased. These observed trends may be due to clinical advantages, technological advancement as well as, other factors such as HCP preference or costs.

The continued rise of UUT stone prevalence has implications for patients, HCPs and hospitals. If we add to that the COVID19 repercussions, solutions to optimize workforce planning, service delivery and length of stay could help to address the situation.

MP04-07 The effect of smaller residual stones after minimal invasive endourology procedures for renal stones: prospective study

N Iqbal, A Hasan, S Imtiaz Ali, S Akhter

PKLI, Lahore, Pakistan

Introduction & Objective: The new era in urology with the advent of minimally invasive surgical techniques has helped in reduction of morbidity associated with surgical treatment of renal stones. Nevertheless, there is lack of agreement as to what has to be done to residual stones, as it has been known that these fragments might have the potential to cause complications after these elective procedures. The objective of our study was to evaluate the natural course followed by residual stones after percutaneous nephrolithotomy (PCNL) or flexible ureterorenoscopy (F‐URS) procedures for treatment of kidney calculi.

Methods: Total of 373 patients were submitted to prospective follow‐up after elective endoscopic procedures such as PCNL and URS for treatment of kidney stones. The presence and features of residual fragments was followed on radiologic scans and the frequency of revisiting hospital for complications or the necessity of additional procedures were sorted out.

Results: The overall stone‐free rate was 76.3% in F‐URS and 67.7% in PCNL. The natural history of 257 patients having residual stone fragments was followed. There was spontaneous passage of these fragments in 13.4% (34) of cases. While 18.2% (47 patients) developed pain or colicky symptoms, 10.5% (26 patients) had complications such as readmission for pain, fever and Urinary tract infection. Total of the 257 patients followed, 16.7% (43 subjects) needed a next surgical procedure. The residual stones larger than 4mm had more complications (p < 0.003), more recurrence of pain symptoms (p = 0.04) and need for additional surgeries (p < 0.002) as compared to the stones of smaller than 4mm in size. Number of the residual fragments even less than 4 mm were more prone to the complications. Size and number of the residual fragments and the multi‐calicial distribution were strong predictors of the development of new symptoms and the need of surgical re‐intervention. (p = 0.04).

Conclusions: Residual stones are frequently seen in endourological procedures for renal stones treatment and might cause morbidity and complications. Number of stone fragements and poles involved have role in these complications. More multicenter prospective studies are needed in this regard.

MP04-08 Total Power is the Most Important Factor Determining Efficiency in Treatment of Large Bladder Stones

M Hajiha, AS Amasyali, M Keheila, J Groegler, A Goyne, D Baldwin, JD Belle, DD Baldwin

Loma Linda University, Department of Urology

Introduction & Objective: Surgeons have a wide array of technology to choose from during laser cystolitholapaxy. Recently, the Lumenis 120W holmium laser with Moses technology and the Olympus 60W thulium laser have been shown to treat renal and ureteral stones efficiently. The purpose of this study was to compare the efficacy and cost of four different holmium laser platforms with the 60W thulium laser in the treatment of a 4cm bladder stone in a benchtop model.

Methods: In a simulated laser cystolitholapaxy, 25 identical 4 cm BegoStones (CaOx monohydrate consistency) were placed on a 5.3 x 5.3 mm mesh in a 3D printed bladder model and fragmented using one of five different laser platforms. The platforms used were the 30W Dornier at 2.5 J/8 Hz (20W), the 100W Olympus Empower at 3.3 J/30 Hz (99W), the Lumenis P120H laser without Moses contact setting at 4 J/30 Hz (120W), the Lumenis P120H with Moses contact setting at 4 J/30 Hz (120W), and the Olympus Soltive Premium TFL 60W at 3J/20 Hz (60W). All lasers were operated at maximal energy using a 550 μm fiber. The cost of the lasers, laser fibers, and procedure time per laser multiplied by the mean cost of OR time ($37/min) were used to model cost effectiveness. ANOVA and Tukey's B post‐hoc analysis were used to compare outcomes.

Results: The Moses laser required less mean lasering time (60.85 min) compared to all other groups (conventional 120W (69.41) min, 100W (79.18 min), TFL 60W (256.3 min), 30W (281.2 min); p = 0.000). Similarly, overall operating time with the Moses laser (68.3 min) was less compared to all others (conventional 120W (86.73 min), 100W (102.8 min), TFL 60W (261.4 min), 30W (297.5 min); p = 0.000). While the 100W and TFL 60W lasers required fiber stripping only 1 and 1.4 times, the Moses, conventional 120W and 30W laser fibers required mean fiber stripping 6.0, 7.8, and 17.4 times, respectively (p = 0.000). Use of the Moses technology would result in an estimated cost savings of $522, $820, $8023 and $6764 per case compared to regular 120W, 100W, 30W lasers and TFL 60W, respectively. When factoring in purchase price, the P120 with Moses became cost effective after 140 cases compared to the 100W laser and only 22 cases in comparison to the 30W laser.

Conclusions: Total power is very important when treating large bladder stones. Based on our model, the Moses contact laser at 120W setting would be the most cost effective in a high volume stone center due to a much shorter operative time. The 100W laser was cost effective in low to moderate volume centers, while lasers with less than 100W of energy are probably not ideal for treating large dense bladder stones.

MP04-09 Effect of Low‐Energy Shock Wave Therapy on Behavioral, Histopathological and Molecular Changes in a Rat Model of Epirubicin‐Induced Cystitis

AH Elkashef, N Barakat, S Khater, A Awadalla, M El‐Ghar, A El‐assmy, K Sheir, A Shokeir

Department of Urology, Urology and Nephrology Center, Mansoura University, Egypt

Introduction & Objective: Epirubicin (EPI) has commonly been used as an adjuvant intravesical therapy for the treatment of non‐muscle invasive bladder cancer (NMIBC). However, its frequent instillation is mainly complicated with cystitis. Low‐energy shock wave therapy (LESW) has been shown to have both anti‐inflammatory and analgesic effects, so we evaluated the effect of LESW on the bladder inflammatory changes associated with EPI‐induced cystitis in rats.

Methods: Thirty female Fischer rats were randomly allocated into 3 groups (10 rats each); Control, EPI and EPI plus LESW groups. Saline (0.6 mL) or EPI (0.6 mg/0.3 mL added to 0.3 mL saline) was instilled and retained in the bladders for 1 hour. LESW treatment (300 pulses, 0.12 mJ/mm²) was applied simultaneously to the bladders in EPI plus LESW group. This was repeated daily for 1 week. Behavioral assessment of pain, eye movement and locomotion was performed 1 hour after instillation. Magnetic resonance imaging (MRI) was also carried out. After sacrification, bladders were harvested for bladder weight estimation, histopathological examination and molecular studies of interleukin (IL)‐6 and tumor necrosis factor (TNF)‐α relative gene expression levels.

Results: LESW significantly improved pain, eye movement and locomotion scores, reduced bladder weights and down‐regulated IL‐6 and TNF‐α expression levels (Table 1). MRI of EPI plus LESW group showed that bladder wall thickness was 0.73 ± 0.25 mm vs. 1.64 ± 0.27 mm in EPI group (p < 0.001) and bladder capacity was 8.7 ± 1.53 μL vs. 5.07 ± 1.31 μL in EPI group (p < 0.001). Yet, there was no significant difference regarding the degree of bladder inflammation between EPI and EPI plus LESW groups (Table 2).

Conclusions: LESW suppresses the bladder inflammatory changes induced by intravesical instillation of EPI, so LESW might be nominated as a promising method for relieving bladder inflammation associated with EPI instillation for the treatment of NMIBC.

MP04-10 Short chain fatty acids reduce renal calcium oxalate stones by regulating oxalate transporters SLC26A3/6 in intestine

Y Liu, X Jin, Y Ma, Z Jian, L Zhou, L Xiang, Q Sun, H Li, K Wang

Introduction & Objective: The prevalence of renal stones is increasing rapidly. The most common component of stones is calcium oxalate (CaOx). High urinary oxalate is a risk factor for CaOx stones. In the gut, the oxalate is secreted by oxalate transporter SLC26A6, and absorbed by SLC26A3. We previously found that the relative abundance of bacteria which produced short chain fatty acids (SCFAs) was lower in the gut microbiota of renal stone patients than healthy people. SCFAs are products from bacterial fermentation of dietary fiber, which had beneficial role in chronic metabolic diseases. The aim of this study was to explore the effect of SCFAs on the formation of renal CaOx stones and demonstrate the involvement of intestinal oxalate transporters in oxalate metabolism.

Methods: Twenty five rats were equally divided into five groups, named control group, model group, acetate group, propionate group and butyrate group. 1% (v/v) ethylene glycol (EG) was added into the drinking water to develop renal CaOx stone model rats. The drinking water of the latter three groups had extra sodium acetate, sodium propionate or sodium butyrate, respectively. Renal crystals were examined using Hematoxylin Eosin (HE) and Von Kossa (VK) staining. The urinary oxalate was measured by liquid chromatography‐mass spectrometry. The gut microbiota was analyzed through 16S rRNA gene sequence. The expression of SLC26A3/6 was measured by quantitative real‐time polymerase chain reaction and western blot.

Results: HE and VK staining showed that there were plenty of crystals in the kidney. Renal crystals reduced after the administration of acetate, propionate or butyrate. The level of urinary oxalate also reduced in rats receiving acetate, propionate or butyrate. The expression of SLC26A3 in the cecum was higher in model group than in control group. It decreased after the administration of acetate, propionate and butyrate. Acetate and propionate increased the SLC26A6 expression in small intestine. Additionally, the relative abundance of Lachnospiraceae, Ruminococcus, Eubacterium and Prevotellaceae were higher in rats receiving acetate, propionate or butyrate, which could produce SCFAs.

Conclusions: SCFAs could reduce urinary oxalate and renal CaOx stones by increasing intestinal SLC26A6 and decreasing SLC26A3 expression. It may provide a new strategy for preventing the occurrence and recurrence of renal CaOx stones.

MP04-11 Extracorporeal shockwave lithotripsy: a good option for treating distal ureteric stones

G Celentano, M Creta, G Cancelmo, F Mangiapia, M Marsicano, M Capece, R La Rocca, G Califano, C Collà Ruvolo, L Napolitano, S Morra, C Turco, C Imbimbo, V Mirone, N Longo

University of Naples Federico II

Introduction & Objective: Extracorporal shock wave lithotripsy (ESWL) is a great option for the treatment of kidney stones but has been accepted worldwide as a reasonable approach to ureteric stones. It is a non‐invasive procedure that uses shock waves to break up stones so they can easily pass through the urinary tract. The recent EAU guidelines state that the ESWL is an appropriate treatment if active stone removal is indicated. The aim was to assess the efficacy of ESWL on distal ureteric stones.

Methods: Between January 2018 to December 2020, 146 patients with monolateral, single, radiopaque and distal ureteric stones without hydronephrosis or with mid or mild hydronephrosis without an acute colic and good renal function underwent ESWL. The stones were identified using the X‐ray guidance (fluoroscopy).

Stone parameters such as size, Hounsfield unit and peri‐operative outcomes like pain (VAS score), complications and stone‐free status were evaluated. A pragmatic view was taken on stone free status, with either Xray or CT, depending on the clinical situation, used to determine this.

The stone‐free status was defined as no residual fragments of any size. Treatment failure was defined as the failure to become stone‐free within 3 months.

Results: The mean stone size was 0.9 cm (0.5– 1.5mm). The frequency of the shockwaves was 120 shocks/min and the mean (range) number of shockwaves delivered during each treatment session was 3200 (2800–4500).

One hundred and twenty three patients (84.2 %) passed the stones and were completely stone free after the treatments.

In 61/123 cases (49.5%), one ESWL session was sufficient to achieve complete stone clearance, while in 52/123 cases (42.2%) and in 21 cases (17,0 %), two and three treatment sessions were required, respectively.

Twenty three patients (15,7 %) required a rigid ureteroscopy for being rendered stone free after a failed ESWL

In 15 cases mild pain was reported. Eleven patients were admitted due to a renal colic and were stented with a double J stent.

No patients required the nephrostomy insertion.

Conclusions: The shock wave lithotripsy could be a valid option for treating ureteric stones once they are visible with the lithotripter. It is safe and not invasive with a small amount of complications. It is not invasive and avoids the general anaesthetic reducing morbidity.

MP04-12 External shockwaves lithotripsy a multi‐institutional international study

M Sighinolfi, M Benedetti, T Calcagnile, A Cassani, M Amato, G Saraceni, N Ferrari, G Bozzini, z ahmed, E Ahmed, E Ahmed, D Cosimo, A Nacchia, P Fedelini, F Chiancone, S Ferretti, p Curti, G Bianchi, BC Rocco, S Micali

Azienda ospedaliero‐universitaria di Modena e Reggio Emilia, Modena, Italy

Introduction & Objective: ESWL is a minimally invasive treatment for small‐medium size urolithiasis. EAU guidelines recommend either ESWL, RIRS and PNL for 10‐20 mm renal stones. ESWL success rate rely on several factors: stone size, location, density, patients' characteristic (BMI) and lithotripter specimens. Endourology advance in technology and procedures decreased the ESWL rate in favor of surgical treatment especially RIRS. The aim of this study is to highlight the role of ESWL in a contemporary series of patients with a single 10‐20 mm renal stone.

Methods: ESWL data were collected prospectively from 6 Italian centers (“Sant'Andrea” Rome, AORN “A. Cardarelli” Naples, “Mater Salutis” Verona, “Maggiore” Parma, University of Modena and Reggio Emilia and Tanta University). We performed a retrospective observational study of data. Inclusion criteria was single renal 10‐20mm stone treated with ESWL. Patients' characteristic analyzed were age, gender, comorbidities, previous surgery, concomitant UTI and stone features (size, location, HU density, stone to skin distance, hydronephrosis). Primary endpoint was stone free rate (SFR: absence of clinically significant residual fragment at 3 months and need for auxiliary procedure); Secondary endpoint was a regression analysis of factors impacting SFR. Data were analyzed with SPSS; after a descriptive analysis, T test for unpaired sample and non‐parametric test (correlation, chi square test) were applied.

Results: 700 patients with a single renal stone were included (440 M, 260 F). Mean age 50,7 yr. (range 18‐96, SD 15). Mean stone size 12,6 mm (range 10‐25, DS 2,8); mean HU density 832 (260‐1643), mean stone to skin distance 89 mm (range 51‐160, SD 16,3). 182 patients had previous renal surgery; 14 patients had a concomitant UTI requiring antibiotic therapy. Renal stone location was pielic in 303 (43%), lower caliceal in 177 (25%), upper and middle calyx in 220 (32%). Pre‐treatment hydronephrosis was evident in 213 (30%). SFR at 3 months was 88,4% (630); of SFR patients, 54,8% were SF after 1 session, the remaining had repeated treatment (21,6% had 2, 17,6% had 3, 10% had ≥4). HU density (p = 0.00) and number of sessions (p = 0.04) were the covariates significantly related to SFR. No major complications occurred.

Conclusions: Our study confirmed the efficacy of ESWL treatment for 10‐20mm renal stones with high success rates. Eligible patients should be counseled on the possibility of repeated sessions, balanced by safety and outpatient feature ‐ without the need for OR availability – particularly fitting the current pandemic scenario.

MP04-13 Is extracorporeal shock wave lithotripsy (ESWL) still suitable for >1.5cm intrarenal stones? Data Analysis of 1902 ESWLs

M Pachecco, E Soares Morales, R Nardi Pedro, L O. Reis, W Azal Neto, L Castro Santos

Endourology Staff UNICAMP, AME/SBO Lithotripsy Center Coordinator, Professor Faculdade São Leopoldo Mandic, Medicine.

Introduction & Objective: According to the AUA and EAU guidelines, ESWL is the least invasive treatment option for stones smaller than 2 cm. However, it is well known that SWL stone‐free rates (SFR) decline as stone size increases. We sought to evaluate whether the size limit of 1.5cm could be a better predictor of success after a single ESWL session than current recommendations.

Methods: Data from an ESWL‐dedicated center were prospectively scrutinized according to stone locations and sizes. Information on patient's demography, lithotripsy parameters, and outcomes was evaluated by multivariate analysis among 1902 consecutive ESWLs.

Results: The overall SFR was 70.8% (1347/1902). SFRs according to Stone size Groups were <1cm: 73.7% (825/1118), 1‐1.5cm: 70.4% (401/569) and >1.5cm: 56.2% (121/215); and according to Stone location groups were lower pole (LP): 64.4% (398/618), mid pole (MP): 73.8% (339/459), upper pole (UP): 73.7% (273/370) and renal pelvis (Pelvis) 74.1 % (337/455). Multivariate analysis revealed better SFR in <1cm and 1‐1.5cm groups (p = 0.000001, p = 0.0003 respectively) and non‐LP groups (p = 0.004).

Conclusions: ESWL is an effective treatment modality for kidney stones with SFRs up to 74.8% for stones <1cm. Patients with stones >1.5cm or >1cm located in LP show significantly lower SFRs after a single ESWL session.

MP04-14 The benefit of obtaining 24‐hour urine testing before prescribing preventive pharmacological therapy to patients with high‐risk urinary stone disease

R Hsi, P Yan, J Crivelli, V Shahinian, JM Hollingsworth

Vanderbilt University School of Medicine

Introduction & Objective: Recent studies show no benefit to a selective approach to preventive pharmacological therapy (PPT) for patients with urinary stone disease (i.e., obtaining 24‐hour urine testing before prescribing). However, these studies estimated the average treatment effect of selective PPT. Because selective PPT may produce nonrandom differences in outcomes across patients based on individual recurrence risk, we compared the frequency of stone‐related events among patients with and without 24‐hour urine testing before PPT use in high‐risk subgroups.

Methods: Using medical claims data (2008 to 2019), we identified working‐age adults with urinary stone disease who had a prescription fill for a thiazide diuretic, alkali therapy, or allopurinol. We stratified them into subgroups based on the presence of a concomitant condition or other factors that raise stone recurrence risk (children, urinary tract infection, gout, bone disease, intestinal malabsorption, hyperparathyroidism, staghorn calculus, renal anomalies, sarcoidosis, cystinuria, and prior stone recurrence). We fit multivariable regression models to compare the frequency of a stone‐related event (emergency department visit, hospitalization, and surgery) among patients with and without 24‐hour urine testing before PPT prescription in these subgroups.

Results: Among 5,275 patients with urinary stone disease who had a concomitant condition or other factor raising their recurrence risk, 37% (n = 1,954) were prescribed PPT after 24‐hour urine testing (median follow‐up, 631 days), while 63% (3,321) received PPT empirically (median follow‐up, 623 days). Patients with prior stone recurrence had a significantly lower hazard of a subsequent stone‐related event if they received selective PPT (hazard ratio, 0.83; 95% confidence interval, 0.71 to 0.96). The adjusted predicted probability of a stone‐related event among patients in this group was five percentage points lower at two years of follow‐up for those on selective versus empiric PPT. No significant associations were noted for selective PPT in the other high‐risk subgroups.

Conclusions: Patients with a history of recurrent urinary stone disease benefit from PPT when guided by findings from 24‐hour urine testing. These data highlight the importance of examining for heterogeneity in treatment effect when comparing stone prevention approaches.

MP04-15 Shockwave Lithotripsy for Distal Ureteric Stones ‐ Results from the Endourological Society T.O.W.E.R. Research Initiative

F Gabrigna Berto, H Razvi, J Bjazevic, VK Wong, L Nott, M Hossny, R Dasgupta, PJ Osther, BW Turney, BH Chew

Western University

Introduction & Objective: Clinical practice guidelines for the treatment of distal ureteral stones are varied. The American Urological Association (AUA) guideline recommends ureteroscopy (URS) as first line treatment while the European Association of Urology (EAU) lists both URS and shock wave lithotripsy (SWL) as potential first line options for stones ˂10mm. Various factors influence stone free rates in SWL patients therefore, patient selection is key. The objectives of this study were to evaluate stone free rates and to identify factors predictive of treatment failure in patients undergoing SWL for distal ureteric stones in four centers from the Team of Worldwide Endourological Researchers (TOWER) from the Endourological Society.

Methods: Consecutive patients undergoing SWL with the Storz SLX‐F2 lithotripter as initial treatment for distal ureteric calculi at four institutions (United Kingdom, Oman and two centers in Canada) were retrospectively reviewed. Treatment success, defined as clearance of the treated stone, was assessed by post‐operative imaging using computerized tomography, plain film x‐ray or ultrasound. Descriptive statistics were used to analyze patients' pre‐operative and post‐operative characteristics. Comparison of means was utilized to assess for predictors of treatment failure.

Results: 384 patients with distal ureteric calculi were treated between October 2011 and November 2020. Mean age was 51.24 years (±15.75) and 67.7% were male. Mean body mass index (BMI) was 28.03 (±5.05 Kg/m²). Mean stone size was 6.51mm (±2.54mm). 83.1% were treated in the supine position and 48.7% of stones were left sided. 236 patients (69.6%) were considered stone free on post‐operative imaging. 38 patients (11.2%) underwent a second procedure (32 URS and 6 repeat SWL). In 64 patients, treatment success was not known and for analytic purposes were assumed to have failed treatment (intent to treat). Patients who failed SWL were older (mean 54.37 ± 15.91 vs. 50.5 ± 15.87), p = 0.036, 95%CI, and had larger stones (7.12 ± 2.85 vs. 6.23 ± 2.19), p = 0.002, 95%CI). Those that failed treatment had a mean larger stone size of 0.89 mm. BMI, gender, total energy, number and frequency of shocks and were not statistically significant.

Conclusions: SWL for distal ureteral stones is an effective treatment option. In this analysis, larger stone size and older patients were predictive of treatment failure and this should be taken into account when counselling patients about their treatment options. SWL should be considered a first‐line option for stones ∼6mm with a 69.6% chance of success.

MP04-16 How Necessary is Post‐Operative Ultrasound Imaging for Ureteroscopic Stone Procedures?

N O'Connell, C Ashley, Z Yasen, R Peggs, J Stephenson, T Tien, R Oliver, P Pal, S Graham

Barts Health NHS Trust

Introduction & Objective: Ultrasound sonography (USS) is a cheap, radiation‐free modality used to diagnose hydronephrosis following ureteroscopic stone procedures for the purpose of detecting potential renal obstruction due to stones or strictures. At our centre there is no protocol for imaging following ureteroscopic stone procedures. We aim to assess the use and efficacy of post procedure USS and outcome in this patient group.

Methods: A retrospective analysis was carried out of 100 consecutive patients who underwent ureteroscopic stone procedures at our teaching hospital in London, UK from the beginning of January 2017 onwards. We reviewed modality and timing of post procedure imaging for the detection of hydronephrosis as well as outcome.

Results: There were 94 patients (6 excluded as solely percutaneous procedures). 31 had semi‐rigid ureteroscopy, 61 had flexible ureteroscopy and 2 had flexible ureteroscopy with percutaneous nephrolithotomy. 57 were left sided, 34 right sided and 3 bilateral. 33 patients were female and 61 were male. Mean age was 52. Average time from operation to USS was 8.4 weeks. 76.6% of patients had USS as the initial post‐operative imaging modality. Sonographic evidence of hydronephrosis was present in 12 of these patients (16.7%) and half of them went on to have CT Urinary Tract (CT). 83% had persistent hydronephrosis on CT (5 patients). Of these, 2 required further procedures for stones and 3 had repeat imaging showing resolving or ‘mild’ hydronephrosis, no further procedures and were discharged to primary care. There were no cases of ureteric stricture reported. 16 patients had a CT rather than USS as their initial post‐operative imaging modality (17%) and 3 had no imaging at all (3.2%). In 44 cases USS was the single modality used throughout the entire treatment episode (46.8%). Outcome as of February 2020 is as follows: 55.3% discharged to primary care (+/‐USS surveillance), 27.7% under urology follow up for stones, 5.3% under urology for other issues, 5.3% lost to follow up, 4.3% did not attend follow up/self‐discharge, 2.1% deceased (for other reasons).

Conclusions: The majority of our patients had USS as the initial imaging modality post ureteroscopy. A small proportion had hydronephrosis and of them none had ureteric strictures but required either further imaging and/or procedures for residual stones. Routine use of USS post ureteroscopy is beneficial both economically and in terms of diagnostic yield as early identification of a potential silent obstruction that requires further imaging is easily achievable and also allows for reassurance in discharging the negative group without exposure to radiation and the higher cost of CT.

MP04-17 Using Artificial Intelligence to Identify Stones on SWL Intra‐Operative Fluoroscopic Images

RG Seltzer, D Soetemans, I Okwuchi, BD Hamilton, SY Nakada

Translational Analytics and Statistics

Introduction & Objective: Most attempts to use Artificial Intelligence (AI) to identify and characterize kidney stones have been from CT scans. While these pre‐operative images are the gold standard for diagnosing urolithiasis, fluoroscopy is the predominant intra‐operative imaging for SWL, used to localize, track, and assess fragmentation of stones. Using AI to identify stones from intra‐operative SWL fluoroscopic images is much more difficult because of the relatively lower image quality and the presence of fragmented or partially disintegrated stones that are not as salient as non‐molested stones. Identifying and characterizing fragmenting stones visible on fluoroscopic images during SWL can help urologists align treatment parameters to the exact stage of stone fragmentation at a specific point in the procedure.

Methods: A labeled dataset of dicom images with stone locations outlined was generated and pre‐processed to generate stone vs. no‐stone images. A Convolutional Neural network was used to extract image features to identify if kidney stone(s) are present on an image via the RESNET deep neural network and Tensorflow. AI algorithms were then used to determine the presence or absence of stones in a set of pre‐defined images.

Results: A total of 6501 static images with stones labeled by 14 technologists were used. A training accuracy of 0.92 and a loss of 0.14, and a validation accuracy of 0.91 and a loss of 0.16 were achieved.

Conclusions: With sufficient data comprising stones in various stages of fragmentation and disintegration during an SWL procedure, AI algorithms showed strong accuracy metrics for identifying stones on fluoroscopic images. Once identified, relevant characteristics of the stone can be extracted and, with additional technology, presented to urologists during a treatment. This intra‐operative feedback may better assist urologists in selecting the optimal shock parameters based on the exact state of the stone.

MP04-18 Medical Impulsive Therapy: Early results from a Randomized Controlled Trial to evaluate tamsulosin use before ureteral access sheath deployment

V Dall'Aqua, A Lopes Neto, A Rodrigues, M Mattos, L Costa, S Glina

Introduction & Objective: As retrospectively proposed by Clayman et al., tamsulosin use before endourological procedures may have an effect in distal ureter that could improve large diameter (16Fr) ureteral access sheath (UAS) deployment. In order to explore this relationship, we conducted the present trial.

Methods: The study is designed to randomize 140 patients in two groups: none pre‐surgical medication (control group) and daily tamsulosin 0,4mg at bedtime one week before surgery (intervention group). All procedure was performed by only one surgeon, which was blind for medication use. An external study coordinator managed the surgery schedule. Primary outcome success was defined as complete UAS deployment. Secondary outcomes were ureteral injury, UAS deployment rate in patients with previous endourologic procedures and patient characteristics (BMI and height).

Results: The preliminary results are demonstrated in table 01. Forty‐two patients underwent retrograde intrarenal surgery (RIRS) and have fulfilled trial requirements. Nineteen patients (45.2%) used tamsulosin before surgery and 23 (54.8%) was in control group. In eight procedures (four in tamsulosin group and four in control) UAS deployment failed. No statistically significant difference was demonstrated (p = 0.764). No difference in UAS deployment rate was observed in patients who had previous endourological procedure (p = 0.166). Patients physical biotype – BMI (p = 0.241) and height (p = 0.09) ‐ did not show differences in UAS deployment rate. Ureteral injury was significantly higher in tamsulosin (42.1% vs. 13.1%) than control group (p = 0.04).

Conclusions: At this moment, in contrast to Clayman et. al. data, no benefit was demonstrated prospectively to support tamsulosin use before surgery when UAS deployment is needed and it uses can elevate ureteral injury rate, as demonstrated in our date. Obesity and lower stature may have a role in UAS insertion failure, but no significant differences were shown. Previous ureteral surgery could work as an obstacle to UAS deployment, due to ureteral reduced complacence, but the trial failed to prove this hypothesis. This is a preliminary trial analysis. Mature data is needed to prove the real effectiveness of tamsulosin use before surgery in UAS deployment rate.

MP04-19 Maternal family history of urolithiasis is associated with earlier onset of urinary stone disease: results from ReSKU

R Unno, K Taguchi, M Usawachintachit, H Yang, F Hamouche, J Ahn, D Bayne, M Stoller, T Chi

University of California San Francisco

Introduction & Objective: Family history of urolithiasis is a known risk factor for kidney stones. The direct relationship between family history and the severity of clinical presentation for kidney stone formers is not yet well documented. In this study, we evaluated the impact of family history on the severity of disease and age of onset in patients with urolithiasis.

Methods: This was an analysis of prospectively collected data from Registry for Stones of the Kidney and Ureter (ReSKU) from a single institution between October 2015 and December 2020. Demographics, clinical, and family history information from urolithiasis patients were collected. The family history information was further characterized to highlight the type of relationship (first vs first‐ and second‐degree relatives) as well as the parental sidedness of the relationship (paternal vs maternal). This detailed family history was then linked to patient clinical data, including number of previous stone episodes, bilaterality, age of stone onset, 24‐hour urine evaluation, and recurrent stone events during follow‐up. Our primary endpoint was the number of patients experiencing at least one recurrent stone event during the study period.

Results: A total of 1566 patients were analyzed for this study. 603 patients (38.5%) had a family history of urolithiasis. On univariate analysis, a positive family history was associated with a higher number of recurrent stone events during the follow‐up period (38.2% vs 27.6% p = 0.001), an earlier onset of kidney stones, a higher percentage of bilateral disease, a higher number of previous stone episodes as well as more significant hypercalciuria on 24 hours urine collections (Table1). On multivariate analysis, any family history was associated with an increased risk of recurrent stone events. The presence of both a first and a second degree relative was associated with the highest odds ratio for recurrent stone event (OR 2.23 p < 0.001), while having a maternal side relative conferred a higher odds ratio for a younger onset of stones (OR 2.53 p < 0.001).

Conclusions: The presence of any family history of kidney stone disease imparts an increased severity of urinary stone disease on patients. Furthermore, the presence of a maternal side relative with kidney stones may be a predictor for an earlier onset of urolithiasis.

MP04-20 Extracorporeal shock wave lithotripsy in patients with spinal cord injury: have contemporary outcomes improved?

MS Yassin, BW Turney, JS Reynard

Oxford University Hospitals NHS Foundation Trust

Introduction & Objective: Spinal cord injury (SCI) is a risk factor for significant urolithiasis. 34% of patients developing one stone will have a second stone episode within five years. Effective stone treatment is essential, as stones are associated with decreasing renal function. We present our extracorporeal shock wave lithotripsy (ESWL) experience in spinal cord injury (SCI) patients.

Methods: We conducted a single centre retrospective study, including all spinal cord injury (SCI) patients who underwent extracorporeal shock wave lithotripsy (ESWL) for urolithiasis from Sep 2013 to Aug 2019. 17 patients underwent 51 treatments and comprised the study cohort. Statistical analysis was performed with SPSS v. 24.0 (IBM Corp, Armonk, NY), and statistical significance was defined as a P‐value of <0.05.

Results: Demographic, stone, treatment and follow‐up parameters are presented in table 1 and 2. Clear stone fragmentation was seen in 19.6% (n = 10), good in 33.3% (n = 17) and satisfactory in 47.1% (n = 24). Post‐treatment stone burden was reduced from a mean of 21.53 (range 39) mm to 13.47 (range 32) mm. 78.6% (n = 11) had their treatment outcome assessed by CT which reflects the lower clearance rate in our series compared others. Pain tolerance was excellent in 84.3% (n = 43), good in 7.8% (n = 4) and satisfactory in 3.9% (n = 2). 5.9% (n = 1) had autonomic dysreflexia requiring treatment termination. No other complications encountered.

Conclusions: Extracorporeal shock wave lithotripsy (ESWL) is a safe, effective and straightforward treatment modality for urolithiasis in spinal cord injury (SCI) patients.

MP04-21 Emergency Ureteroscopy Service Reduces Patient morbidity and need for secondary procedures in Acute Stone Patients

A Jha, C Ho, S Lee, S Albuheissi, F Keeley, A Timoney, J Philip

Bristol Urology Institute

Introduction & Objective: 60% of patients attending hospitals with acute stone colic are treated conservatively during their acute presentation, a reported median of 20% of patients had a ureteric stent insertion in all NHS trusts in England. We aim to assess the outcome after introduction of dedicated emergency ureteroscopy theatre slots to help reduce the demand on generic emergency lists and to improve patient outcomes.

Methods: A prospective study over a 3‐month period ending January 2020 following the introduction of emergency ureteroscopy (URS) care pathway with dedicated theatre slots, in a teaching hospital in UK. Predating retrospective study of all patients admitted with ureteric colic/ obstructing ureteric stones over three months ending December 2018 was the initial pilot study to identify the acute burden of stones.

Results: Between October and December 2018, 42% underwent conservative management during initial presentation while 42% had ureteric stent inserted (antegrade or retrograde). 4% underwent primary URS and 7% underwent emergency ESWL (Extracorporeal Shockwave Lithotripsy). 4 patients (8%) represented to the hospital within 28 days.

Conclusions: Almost a fifth of the emergency urology admissions and a third of the emergency surgical procedures are stone related. The emergency ureteroscopy pathway reduces patients having temporising stents by half and the need for secondary procedures. Emergency ESWL uptake almost tripled; with primary emergency ureteroscopies increasing fivefold. Implementing a Primary Ureteroscopy pathway has reduced stone patient morbidity, stent insertions and need for secondary procedures with improved quality of life.

MP04-22 Matched Pair Analysis of Extended versus Precise Focus Shockwave Lithotripsy for Urolithiasis

AJ Sharp, CE Lovegrove, R Sreekumar, M Spencer, BW Turney, SA Howles

University of Oxford

Introduction & Objective: Evidence for the optimal focus size during shockwave lithotripsy (SWL) for urolithiasis is lacking. To increase understanding, we compared stone clearance and complication rates when using an ‘extended’ focus treatment field (9 x 50mm) to a ‘precise’ field (6 x 28mm), when undertaking SWL in patients with renal or ureteric calculi.

Methods: Data from patients undergoing SWL to renal or ureteric stones using a Storz Modulith SLX‐F2 lithotripter at a single centre were prospectively collected between February 2018 to September 2020. A precise focus treatment field was used until July 2019; after this date, an extended focus treatment field was employed. Patients were matched according to stone size, location, and number of SWL treatments. Stone clearance rates, re‐presentation to hospital within 31 days, symptoms, complications, and subsequent treatment were recorded, and compared using McNemar's test. Energy level reached during SWL was compared using the Wilcoxon signed‐rank test.

Results: In total, 152 patients received extended focus SWL, and were matched with 152 patients treated with precise focus SWL. Median stone size was 6mm (IQR 5‐7mm). Maximum energy delivered was comparable between groups (p = 0.08, median maximum energy level of 6 for both groups). Extended focus SWL achieved complete stone clearance in 55% of patients (N = 84), compared to 41% (N = 63) in the precise focus group (p = 0.009). Complete clearance was defined by a lack of residual fragments on follow‐up plain radiograph, ultrasound, or non‐contrast CT. Where overall treatment success was defined as having no need for further follow up or treatment of the index stone, use of the extended focus resulted in a 74% success rate (N = 113) compared to 66% (N = 100) of precise focus patients (p = 0.05). Extended focus SWL was also associated with greater rates of urinary tract infection and requirement for analgesia (7% (N = 10) versus 1% (N = 2), p = 0.02, and 17% (N = 26) versus 9% (N = 14), p = 0.046, respectively). No differences in rates of re‐presentation to hospital, haematuria, or treatment of complications under general anaesthetic were identified.

Conclusions: This study indicates that extended focus SWL results in greater complete stone clearance, and may improve overall treatment success rates. However, extended focus treatment was also associated with increased rates of post‐procedural infection, and requirement for analgesia. Our findings will inform urologists and radiographers when evaluating the relative advantages and disadvantages of each focus size during SWL.

MP05-01 Suction Assisted Mini Percutaneous Nephrolithotomy as a day care procedure for medium sized renal stones

MS Agrawal, D Mishra

Global Rainbow Hospital, Agra, India

Introduction & Objective: Mini PCNL (Percutaneous Nephrolithotomy) with Laser lithotripsy has been a modality of choice for medium sized renal stones. Vacuum cleaner effect works very effectively for removal of stone fragments. We evaluated the use of Suction in Mini PCNL to augment the vacuum cleaner effect and also lowering the Intra Pelvic Pressure(IPP) using a specially designed SHAH sheath in our center.

Methods: Data was collected prospectively from 64 consecutive patients undergoing Mini PCNL for medium sized renal stones (>1cm, <2.5cm) from January 2019 till December 2019. All patients underwent a preoperative evaluation and Non Contrast Computer Tomography(NCCT) scan to assess stone burden. We used 12 Fr Mini Neproscope(Karl Storz, Gemany) for all cases. The initial steps of puncture were same as standard PCNL. Tract Dilation was single step. Stone fragmentation was performed using holmium laser. The metallic Super‐perc sheath has a rear suction channel, allowing application of surgeon‐controlled suction to the outflow tract, thus helping extraction of the fragments and keeping IPP low.

Results: Mean age of the group was 43.5 years (range 18‐76) with 40 males and 24 females. Mean stone size was 16.5mm (range 10‐25mm) and mean operative time was 43.9 min (range 25‐90 min) with mean fragmentation and removal time of 28.4 min(Range 18‐60 min). 6 renal units had upper calyceal puncture whereas 30 had middle, 24 lower calyceal and 2 with two punctures. DJ stent was placed in 18 patients whereas 46 patients were totally tubeless, with only a ureteric catheter left indwelling overnight. No patient required a nephrostomy tube and surgical site was sutureless in 54 cases. The mean Hemoglobin drop was 0.24 units with no blood transfusion. Post‐op 2 patients reported fever and 3 had minimal hematuria. 7 patients had minimal discharge from surgical site. The mean hospital stay was 22.5 hours with most patients discharged within 24 hours of admission. The stone clearance rate on follow‐up NCCT was 96.8%. The follow up was for 3 months duration.

Conclusions: Suction assisted Mini PCNL has outstanding stone clearance rates in medium sized renal stones with good safety profile.

MP05-02 Comparison of pain scores and recovery after Percutaneous Nephrolithotomy in patients with and without regional anesthesia block. Prospective Randomized controlled study

N Iqbal, A Hasan, S Imtiaz Ali, J Rahim, S Akhter

PKLI, Lahore, Pakistan

Introduction & Objective: Achieving effective pain control is vital for early patient mobilization and eventually returning back to normal routine life following percutaneous nephrolithotomy (PCNL) surgeries. The use of an intraoperative local anesthetic or postoperative analgesic has been reported for pain control in PCNL. Erector spinae block is a regional anaesthetic technique applied in other surgeries under ultrasound guidance. The aim of our study was to see the effectiveness of this block on postoperative pain in PCNL.

Methods: This prospective, randomized, double‐blinded study was carried out since May 2018 till September 2019. The Erector spinae block was administered to a total of 47 patients who had undergone elective PCNL under General anesthesia. While other group of the patients (Group 2, n = 67) didn't receive such block. Postoperatively the pain level was measured using the visual analog scale (VAS), and the opioids consumptions at the postoperative 1, 2, 6, 12, 18, 24, 48 and 72 hours.

Results: The postoperative VAS was found to be statistically significantly lower in the Erector spinae block group (2.1) as compared to the group without Erector spinae block (mean VAS score = 3.2, p < 0.05). The postoperative opioid analgesic use was found to be statistically significantly higher at the 3hours, 6 hours, 12 hours, and 24th hour in Group without Erector spinae block (p < 0.05).

Conclusions: The Erector spinae block was observed to be effective in pain control and reducing opioid use during the postoperative 48 hours follow‐up after PCNL. It may help in avoiding the use of opioids keeping in view the opioid epidemic challenges nowadays.

MP05-03 Withdrawn

MP05-04 The Use of Peripheral Nerve Blocks Provides a Significant Opioid‐Sparing Analgesic Effect for Percutaneous Nephrolithotomy: A Systematic Review

R Alam, K Koo, BR Matlaga, JS Winoker

Johns Hopkins University School of Medicine

Introduction & Objective: Multimodal analgesia regimens incorporating peripheral nerve blocks (PNB) have demonstrated reduced postoperative pain, opioid use, and recovery time in various disease states. However, this remains a controversial subject of limited investigation in the percutaneous nephrolithotomy (PCNL) domain. In the face of an ongoing opioid epidemic and collective push to enhance prescribing stewardship, we sought to examine the evidence for PNB in PCNL.

Methods: A systematic review of Embase and PubMed was performed to identify all randomized controlled trials evaluating the use of a PNB with general anesthesia (GA) versus GA alone for pain control following PCNL. Studies evaluating neuraxial (epidural and spinal) anesthesia, those without GA as the control arm, and those not evaluating pain scores were excluded. Pain scores up to 24 hours after surgery were based on visual analog scale (VAS). Due to study heterogeneity, meta‐analysis of effect sizes was deemed inappropriate and outcomes were summarized descriptively, except where pooled analysis was suitable.

Results: Sixteen trials evaluating 878 procedures were included (Table). Five different blocks were identified and evaluated: paravertebral (PVB, n = 8 studies), intercostal nerve (ICNB, n = 2), quadratus lumborum (QLB, n = 2), transversus abdominis plane (TAPB, n = 1), and erector spinae (ESB, n = 3). Nine studies observed lower pain scores with PNB use throughout the 24‐hour postoperative period. By contrast, 5 studies showed improved pain scores with PNB that was limited to the early (< 6 hours) recovery period, and 2 studies found no difference. However, the total analgesia requirement was significantly higher in the control arm in 5 of these 7 studies and in 11 of 13 studies overall. Operative times were similar, and there were no differences in rates of intercostal access or nephrostomy tube insertion between study arms within any trial.

Conclusions: While greater pain medication use with GA alone likely minimizes or obscures differences in patient‐reported pain scores, PNBs may offer a significant opioid‐sparing analgesic effect for PCNL.

MP05-05 Withdrawn

MP05-06 Feasibility of a Non‐opioid Pathway Post Ureteroscopy: Joint Analysis from Two Academic Centers

M Awad, M Assmus, a Berg, M Lee, L Hallgarth, AE Krambeck, K Sternberg

Northwestern University, Department of Urology

Introduction & Objective: In an effort to combat the alarming amount of postoperative opioid prescribing in the United States (U.S.), many surgical specialties are implementing pathways to limit the routine use of postoperative opioids with the goal of zero opioid prescribing. We sought to examine the durability of established non‐opioid post ureteroscopy (URS) pathways previously implemented at two academic urology centers in the U.S.

Methods: We examined patients who underwent URS at two academic centers utilizing a non‐opioid postoperative pathway between November 2016 to March 2020. Primary outcomes evaluated included adverse events (Emergency Department (ED) presentation, and Office phone calls for postoperative genitourinary symptoms) for patients discharged with and without opioids. Secondary outcomes were factors associated with adverse events.

Results: In total, 699 patients underwent URS with stent placement. Of these, 652 (89.4%) were discharged without opioids and 74 (10.6%) received opioids postoperatively. Of those discharged without opioids, 484 (77.4%) received non‐steroidal anti‐inflammatory medications. The majority of patients were prescribed adjunct medications (acetaminophen, phenazopyridine, and/or tamsulosin) upon discharge. Compared to patients discharged without opioids, patients who were prescribed opioids were more likely to present to the ED (67 (10.7%) vs 14 (19.9%), p = 0.037) and call the clinic postoperatively for genitourinary symptoms (102 (16.3%) vs 22 (29.7%), p = 0.004). In a multivariate analysis, patients prescribed opioids post URS (OR 1.9, 95% CI 1.1 – 3.5, p = 0.024) and patients who had an opioid prescription preop (OR 2.2, 95% CI 1.1 – 4.5, p = 0.032) were associated with higher odds of calling the clinic for genitourinary symptoms. Older patients (OR 0.98, 95% CI 0.97 – 0.99, p = 0.006) were less likely to call the clinic for genitourinary symptoms.

Conclusions: The study highlights that almost 90% of patients can be discharged safely without opioids following URS. In our cohort, patients prescribed opioids experienced higher postoperative healthcare interactions (ED visits and office phone calls). We hope our results will encourage other urologists to consider non‐opioid pathways post URS.

MP05-07 The effect of topical tranexamic acid on postoperative hemoglobin level in patients undergoing PCNL

S Farshid, V Rezvankhah, N ahmadian, M sadri

Introduction & Objective: PCNL is a selective treatment for kidney stones larger than 2 cm in diameter and many smaller stones. One of the side effects of PCNL is hemorrhage, for which interavenous tranexamic acid may be used. There is no study on the effect of topical tranexamic acid on the prevention of bleeding during PCNL but there are studies in orthopedic and maxillofacial surgeries showed the efficacy of topical tranexamic. This study was performed to compare the rate of postoperative hemoglobin loss in patients undergoing PCNL using topical tranexamic acid in nephrostomy compared with control group.

Methods: In this double‐blind clinical trial study, 90 patients undergoing PCNL were randomly divided into two groups, topical tanzanexamic acid and control (without tranexamic acid injection). Inclusion criteria were age between 18‐65 years, ASA class

Results: The mean age of patients in this study was 45.21 ± 11.69 years and there was no significant difference between the two groups (p = 0.058). There was no significant difference between the two groups regarding hospital stay and its mean was 2.34 ± 0.83 days. Hemoglobin loss was ‐1.19 ± 1.28 in tranexamic acid group and ‐3.07 ± 1.20 in the control group (t = 7.141, p = 0.001). Comparison between groups was statistically significant (p = 0.001) after hemoglobin surgery. Regarding stone free rate, the two groups had similar status and about 72% in intervention group and 70% in control group. There was no significant difference between the two groups in the time of surgery, in such a way that in the tranexamic acid group was 82.57 ± 33.57 minutes and in the control group was 87.15 ± 33.39 minutes (p > 0.05).

Conclusions: This study showed that topical application of tranexamic acid after the end of PCNL can prevent hemoglobin loss in patients with low preoperative hemoglobin level, as well as in cases of longer surgical length or large and numerious stones. Those who are more likely to bleed can reduce the amount of bleeding using topical tranexamic acid.

MP05-08 Safety and feasibility of intraoperative real‐time digital stone fragment measurement during ureteroscopy

R Becker, K Koo, T Aro, JS Winoker, S Lim, D Petrisor, D Stoianovici, BR Matlaga

James Buchanan Brady Urological Institute, The Johns Hopkins Medical Institutions

Introduction & Objective: Estimating the size of stone fragments during ureteroscopy is critical for determining the adequacy of stone fragmentation, likelihood of spontaneous fragment passage, and ability to safely extract fragments through the ureter or ureteral access sheath. We previously developed and validated an image processing software that enables digital measurements of stone fragment size during ureteroscopy. This study assesses the safety and feasibility of performing real‐time in vivo stone fragment measurement and integrating its use into live operating room workflow.

Methods: Adult patients >18 years old undergoing ureteroscopic stone procedures for renal or proximal ureteral calculi by 2 surgeons at a single center were enrolled prospectively. The software was used to perform a representative series of real‐time intraoperative stone fragment measurements. The time required to perform each measurement or series of measurements was recorded, including snaring the fragment with a stone retrieval basket, initiation of the digital measurement by the surgeon, and confirmation of size calculation. Software‐related failures, clinical complications, and delays were also recorded. Ethics approval of the feasibility study protocol required that the measurements have no impact on clinical decision‐making; thus surgeons were blinded to the results.

Results: Nine patients undergoing ureteroscopic stone treatment were enrolled. Median age was 50 years (range 25‐75). Six (67%) patients were female. Five (56%) procedures were right‐sided. Intraoperative real‐time measurement of stone fragments was successfully completed in all patients. The median number of measurements performed was 5 (range 3‐10). The mean time for each measurement, from snaring the fragment until size calculation, was 9.9 seconds (s) (range 7.1‐14.9 s). The median total time spent performing digital measurement per procedure was 50 s (range 25‐99 s). There were no technical failures of the software or ureteroscope. No measurement‐related delays or clinical complications were observed peri‐operatively.

Conclusions: Intraoperative digital stone measurement can be safely performed during ureteroscopy and integrated into operating room workflow, with minimal additional time and no observed complications. These data support a prospective trial of digital stone measurement to guide intraoperative decision‐making.

MP05-09 In‐Vivo Porcine Evaluation of the Thermal Effects of the Superpulse Thulium Laser Lithotripsy during Ureteral Stone Laser Lithotripsy

P Jiang, A Peta, M Ayad, A Brevik, K Larson, Z Okhunov, RM Patel, T Farzaneh, J Landman, RV Clayman

Department of Urology, University of California, Irvine

Introduction & Objective: The superpulse thulium fiber laser (sTFL) is a promising emerging technology for laser lithotripsy; however, there have been concerns due to its thermal output which in the kidney may exceed 44°C, the threshold for thermal cellular injury. Given the limited space within the ureteral lumen, we sought to evaluate the thermal effect on the ureter of sTFL for treatment of ureteral stones in an in‐vivo porcine model.

Methods: One juvenile female Yorkshire pig was used for the in‐vivo study (three trials in each ureter). Via an open surgical pyelotomy from an extraperitoneal approach, calcium oxalate stones (total of 6 stones) measuring 3‐4mm were deposited into each ureter at three locations (distal, mid, and proximal) via antegrade ureteroscopy using a nitinol 4‐wire basket. Two K‐type thermocouples were placed (one inside the ureteral lumen and one adjacent to the adventitia of the ureter. Retrograde flexible ureteroscopy (37°C warmed irrigation at 100mmHg) and laser lithotripsy was performed with a 200μm sTFL fiber with dusting settings of 0.2J, 80Hz (16W). Each stone was dusted for a maximum of five minutes, with lithotripsy paused whenever either thermocouple reached 44°C; lithotripsy was resumed once the thermocouple cooled to 37°C. The time to peak temperature as well as cooldown to body temperature and baseline temperature were recorded. Ureters were harvested for histopathologic analysis.

Results: Upon initial laser activation during the 6 trials, the intraluminal thermocouple registered 44°C at 83 ± 45 seconds (mean ± SD) of lasing; however, the peri‐ureteral thermocouple never reached 44°C (max 40.3°C). After the inside thermocouple peaked at 44°C, it required an average of 4 ± 4 seconds (mean ± SD) to cool down to 37°C. With each subsequent laser activation, it took an average of 6 ± 5 seconds (mean ± SD) to peak to 44°C; however, under no circumstance did the adventitial thermocouple reach 44°C.

Conclusions: The use of the superpulse thulium fiber laser (sTFL) for dusting ureteral stones results in rapid elevation of intraluminal temperatures at the level of the urothelium; however, this is not mirrored at the level of the ureteral adventitia. Cessation of lasing resulted in rapid cooling of the temperature. We recommend utilizing short 5 second bursts of laser activation when performing lithotripsy in the ureter to avoid exceeding intraluminal temperature above 44°C.

MP05-10 Adaptive Percutaneous Nephrolithotomy: Modifying Positioning & Access for Each Patient

N Nimmagadda, CM Forbes, NL Kavoussi, R Hsi

Vanderbilt University Medical Center, Department of Urology

Introduction & Objective: Surgeons typically perform percutaneous nephrolithotomy (PCNL) in a preferred position using one access method. We sought to evaluate the feasibility and outcomes of an “adaptive PCNL” approach – adapting positioning and access techniques to patient and stone characteristics, performed during a learning curve period for PCNL.

Methods: All PCNL cases performed by a single surgeon immediately after fellowship training (primarily prone PCNL with fluoroscopic access), were retrospectively reviewed from 9/2016 ‐ 5/2020. Positioning was categorized as prone ± split leg, supine (0 degrees), modified supine (15‐45 degrees), or flank (>45 degrees). Access was achieved with fluoroscopic, ultrasound, and/or endoscopic guidance. We evaluated differences in patient factors and outcomes across positions, and then evaluated the learning curve necessary to achieve stability in procedure time.

Results: Among 19 PCNLs performed, prone PCNL comprised the first 23 cases. Positioning subsequently varied every 1.67 cases on average with 49% performed supine/flank (Figure 1). Prone PCNL was more commonly associated with fluoroscopic access, larger stone size, and bilateral PCNL, whereas modified supine cases were associated with ultrasound ± endoscopic access, and contralateral ureteroscopy or lower urinary tract procedures (Table 1). No differences were seen in upper pole stone location or access (p = 0.13 and p = 0.08, respectively). The second 32 cases had significantly higher mean procedure time vs the subsequent groups of 32 cases (164.2 min vs 112.0‐125.4 min, respectively, p < 0.01). Needing fluoroscopy during access decreased over the learning curve (p < 0.01). Mean residual fragment size was less in the latter 96 cases (0.289 vs 0.469 mm, p = 0.01).

Conclusions: Adaptive PCNL is feasible for optimizing procedural complexity, operative time, and fluoroscopy. The learning curve for adopting adaptive PCNL is comparable to other series utilizing fixed techniques.

MP05-11 Holmium laser lithotripsy with Moses^™ Technology in percutaneous nephrolithotomy: preliminary results from a comparative study

E Lievore, S Zanetti, M Turetti, L Boeri, M Fontana, A Gallioli, F Longo, E De Lorenzis, G Albo, E Montanari

Dept. of Urology, Foundation IRCCS Ca’ Granda Ospedale Maggiore Policlinico, Milan

Introduction & Objective: Moses^™ is a pulse delivery technology aiming to maximize laser energy transmission in lithotripsy. The aim of this study is to compare efficacy and safety of Moses Lumenis Pulse (LP) 120W laser and VersaPulse PowerSuite (VPPS) 100 W laser during aspiration‐assisted mini‐percutaneous nephrolithotomy (vmPCNL).

Methods: We prospectively collected data from 20 consecutive vmPCNL procedures performed with the VPPS laser from November 2018 to March 2019, and 20 consecutive vmPCNL procedures performed with the Moses LP laser from March to October 2019 in a single center. All procedures were performed with a Storz MIP 12 Fr nephroscope and 16 Fr Clear Petra nephrostomic sheath with aspiration. Collected data included patients' and stones' characteristics, intra‐ and post‐operative data, complete stone‐free (SF) status at the 45 days CT scan and complications according to the Clavien score. These variables were compared between the two groups

Results: Results are shown in Table 1. The two groups resulted homogeneous in terms of patients' and stones' characteristics. The overall median stone volume was 1,83 cm³. No significant differences were observed in procedural times, laser total energy and haemoglobin drop. In the Moses group no high grade (Clavien >2) complications were recorded, in the non‐Moses group one Clavien 3A complication (i.e. renal colic needing DJ stent positioning) was reported. The SF status was obtained in 15 patients in the Moses group and in 10 in the non‐Moses group. All other patients had residual fragments <5 mm except from one patient in the LP group who was retreated in a pre‐operatively planned multi stage treatment

Conclusions: The Moses^™ technology seems to be as safe and effective as the standard Ho:YAG laser. Although no significant differences were reported, we noted a tendency towards lower laser energy, lasing time and combined lithotripsy and lapaxy time in the Moses group. In addition, in this group we reported a 50% increase in the SF rate. Probably, the Clear Petra aspiration‐assisted system, by quickening the procedure and enhancing fragments lapaxy in both groups, could play a confounding role in evaluating laser contribution to procedural times and SF rates. However, this study sample is too small to draw firm conclusions and the descripted tendencies may be confirmed with further studies

MP05-12 Factors affecting the ability to offer emergency primary ureteroscopy in a tertiary teaching hospital

C Fontaine, R Sehgal, Y Abu‐Ghanem, L Forster, G Ellis, P Singh, R Kucheria, A Goyal, D Allen, L Ajayi

Introduction & Objective: According to current UK NICE guidelines, definitive treatment (primary ureteroscopy (URS) or shock wave lithotripsy (SWL)), should be offered to patients with symptomatic renal colic (ongoing pain) or likely impassable stone, within 48 hours of diagnosis. In the current analysis, we aim to review the factors that may influence the ability to achieve these guidelines in a well‐resourced tertiary centre in Central London.

Methods: Retrospective review of all patients presenting to the emergency department at our institution between January 2019 and December 2019 with the diagnosis of a ureteric or renal stone. The emergency intervention rate, risk factors for intervention, and other qualitative data were analysed.

Results: A total of 258 patients required surgical management for symptomatic ureteric colic. Of those, 91 patients (35%) underwent definitive treatment by either primary URS (82 patients) or ESWL (9 patients), at a mean time to procedure of 25.5 hours (range 1 – 118). Majority of patients (50/82 61%) undergoing primary URS had distal ureteric stones compared to a preference of proximal ureteric stones in SWL (5/9 56%) and those undergoing emergency stenting alone (116/167 69%). Primary URS was more likely to be performed in a supervised setting compared with emergency stenting; resident supervised 51%, resident alone 31% and consultant alone 18%. A larger mean stone size was associated with emergency stenting (7.8mm versus 6.9mm for primary URS and 6.2mm for SWL).

Conclusions: Although definitive treatment carries high success rates, in a high‐volume tertiary referral centre, it may not be feasible to offer it to all patients, with emergency stenting providing a safe and quick interim measure. Factors determining the ability to provide definitive treatment are stone location, stone size and resident supervision in theatre.

MP05-13 Dusting Efficiency of the Moses Pulse 120H 2.0 Laser System: An In vitro Assessment

P Whelan, CJ Kim, D Ho, C Tabib, F Soto‐Paulo, J Chen, P Zhong, GM Preminger, M Lipkin

Duke University

Introduction & Objective: Moses^™ Pulse 120H 2.0 Extended Frequency Range (EFR) technology is a second‐generation Holmium:YAG laser system designed to introduce higher frequency pulse settings. Our aim is to assess the efficiency of Moses 2.0 technology lithotripsy in an automated in vitro “dusting model.”

Methods: All tests were conducted using a Moses^™ Pulse 120H 2.0 laser system on “hard” (5:1) and “soft” (5:2) Begostone phantoms. Treatment efficiency is compared between Moses Distance (MD) and Moses EFR settings of comparable power (0.3J/80Hz MD to 0.2J/120Hz EFR; 0.4J/80Hz MD to 0.3J/120Hz EFR) at a fiber‐stone standoff distances (SD) of 0 and 1mm. The laser fiber was scanned in a spiral to deliver 1kJ of energy over a 1 cm² area with a 3D positioning system across a polished and submerged Begostone surface. Stone mass loss was compared following treatment. Additionally, the ablation efficiency of MD vs EFR pulses trough segments at an adjusted fiber scanning rate of 50 pulses/mm was compared across equivalent energies (0.2, 0.3, and 0.4J). Ablation volumes of 1 mm trough segments were quantified by optical coherence tomography (OCT).

Results: In spiral scan testing, EFR was similar or slightly superior to MD (Figure 1). At SD 0mm, EFR had superior trough ablation volume to MD across all pulse energies (p < 0.05) by approximately 20‐80%. This is most prominent at lower energy and soft stones. Ablation volume increased with increasing pulse energy. There was little damage observed at SD 1mm.

Conclusions: The EFR provided by Moses 2.0 technology offers superior trough ablation volumes, although this does not translate into spiral scan mass lost. The Moses 2.0 treatment modes may offer a more efficient treatment method in practice by lowering retropulsion with lower pulse energy while negating loss in ablation efficiency with higher pulse frequency.

MP05-14 Reducing the rate of negative ureteroscopy: predictive factors and the role of pre‐ureteroscopy imaging

AC Brodie, TJ Johnston, P Lloyd, L Hemsworth, S Keoghane, M Barabas

Mr

Introduction & Objective: In an increasingly litigious healthcare environment, a negative ureteroscopy (URS) performed for an already passed ureteric calculous exposes the patient to unnecessary risk and represents an avoidable misuse of resource. This study investigates the factors predictive of negative URS and assesses the impact of pre‐operative imaging in reducing the rate of unnecessary negative URS.

Methods: A single‐centre retrospective review was performed for all patients who underwent emergency ureteric stenting for a ureteric calculous during two study periods; April 2011 to February 2016 and October 2016 to October 2019 in the second cohort. From October 2016 onwards change pre‐URS imaging was introduced in the form of computed topography (CT) or abdominal x‐ray (AXR). Data collected included patient demographics, indication for stent, stone characteristics, baseline bloods, admission urine culture, stent duration, re‐admission rate, negative URS rate and the use of pre‐URS imaging. Multivariate logistic regression and Pearson's Chi‐square were used for statistical analysis.

Results: In total 257 patients underwent emergency insertion and deferred URS for ureteric calculous. The mean age was 56. Indications for stent insertion were pain (n = 109, 42%), sepsis (n = 101, 39%) and acute kidney injury (n = 47, 19%). Mean stone size was 7.8mm (range 2mm‐25mm), mean stone density was 702 Hounsfield units (HU) (50 – 1588HU) and the stone locations were upper (n = 160, 62%), mid (n = 32, 13%) and lower ureter (n = 65, 25%). In the initial cohort the negative URS rate was 14% decreasing to 9%. In the second cohort and 7 patients avoided URS altogether due to pre‐op imaging. Analysis of the entire cohort revealed a negative URS rate of 14% in the non pre‐URS imaged patients compared to 6% in pre‐URS imaged patients (p = 0.19). Multivariate logistic regression analysis revealed stone size <5mm (ß = 0.75, 95% CI: 0.60‐0.94 p = 0.011) was predictive for negative URS.

Conclusions: This study demonstrates that pre‐URS imaging leads to a clinically significant reduction in negative URS rate. Furthermore, stone size <5mm is predictive for negative URS and represent the subgroup most likely to benefit from pre‐URS imaging.

MP05-15 Risk of unplanned postoperative re‐admissions in children undergoing ureteroscopy: a post‐hoc analysis of the pediatric National Surgical Quality Improvement Program database

Y Ding, J Davidson, EP Chan, J Bjazevic, G Filler, S Dave, Z Wang

Western University

Introduction & Objective: The incidence of pediatric urolithiasis has increased over the last two decades. Ureteroscopy (URS) with laser lithotripsy is currently recommended for the treatment of mid to distal ureteral calculi; however, there is currently no consensus regarding whether URS is appropriate for all pediatric patients. We aimed to examine the risk of unplanned postoperative hospital readmissions in children undergoing URS.

Methods: A post‐hoc analysis of data collected from the American College of Surgeons National Surgical Quality Improvement Program^® (ACS NSQIP) Pediatric Version. The ACS NSQIP Pediatric datasets are validated and risk‐adjusted and include 127 institutions across Canada and the US to date. This study examined the outcomes of 299,865 pediatric patients with urolithiasis who underwent URS between 2015 and 2017. These children were identified using the International Statistical Classification of Diseases and Related Health Problems (ICD) codes ‐ 9th and 10th revision and by the Current Procedures Terminology (CPT) codes for URS.

Results: A total of 1,122 pediatric URS cases were identified. The median age was 14.4 years (interquartile range [IQR]: 10.2‐16.5) and 55.4% of these cases were female. Overall, 8.9% of URS cases required a re‐admission to hospital within 30 days of the index procedure, and of these 71% were unplanned re‐admissions. The two most common reasons for unplanned re‐admissions were postoperative urinary tract infections (UTIs, 26.4%) and persistent ureteral calculus (21.8%). On univariate analysis, children with unplanned re‐admissions were significantly younger in age (median 11.3 years; IQR 8.3‐16.7) compared to those without unplanned re‐admissions (median 14.5 years; IQR: 10.5‐16.5; p = 0.028). The relative risk (RR) of an unplanned readmission was 2.4 times higher for children aged 6‐11 years (95% confidence interval [CI]: 1.51‐3.93), and 4.5 times (95% CI: 1.80‐11.50) for children under 2 years old when compared to children 12‐18 years old.

Conclusions: Our study demonstrates that younger children undergoing URS are at a higher risk of unplanned re‐admissions secondary to postoperative UTI and persistent calculi. As such, age should be taken into consideration when deciding on the optimal surgical modality or perioperative care for children with urolithiasis. Further prospective studies are needed to better elucidate the indications of URS for pediatric urolithiasis, as well as the postoperative management and outcomes of these children.

MP05-16 Mini percutaneous nephrolithotomy using SuperPulse Thulium Fiber Laser: Evaluation of clinical efficacy and safety

DA Sytnik, S Popov, I Orlov, I Pazin, M Suleymanov, A Kulikov

St. Luke's Clinical Hospital

Introduction & Objective: As a rule, the Ho: YAG laser was used as a source of lithotripsy when performing mini percutaneous nephrolithotomy (miniPCNL) due to its high efficiency and safety. But in recent years the SuperPulse Thulium Fiber Laser (SPTFL) has become more and more interesting. The aim of this work was to evaluate the clinical efficacy and safety of the miniPCNL using SPTFL.

Methods: The study included 53 patients who underwent miniPCNL including 30 men and 23 women. The average age of the patients was 61 ± 13 years. Average stone size 26.32 ± 5.56 mm, with an average density of 1165 ± 314 Hu. Exclusion criteria: multiple renal stone, stone size larger than 3 cm and less than 1 cm, urinary tract abnormality Surgical technique: miniPCNL was performed with tract dilatation up to 15/16 Fr (Karl Storz, MIP M) in the patient's supine position. The energy source for lithotripsy was a SPTFL (IPG Photonics, FiberLase U2), fiber thickness 400 μm. The fragmentation of the stone occurred in the dusting mode (0.2 J, 150‐200 Hz). On the 1st day computed tomography of kidneys, ureter and bladder was performed to evaluate the SFR level. The following parameters were evaluated: time of surgery; lithotripsy time, SFR level; exit strategy; postoperative complications according to the Clavien‐Dindo classification.

Results: The average duration of surgery was 34.8 ± 14.7 minutes. Lithotripsy time: 806.73 ± 487.6 seconds. Drainage methods: Totally tubeless ‐ 12 cases (22.64%), Tubeless (JJ stent) ‐ 25 cases (47.17%), nephrostomy tube ‐ 16 cases (30.19%). SFR ‐ 96.3%. Complication was registered in 3 patients, namely urinary tract infection (Clavien‐Dindo 2) ‐ 2 patients; renal colic initiated by blood clots ‐ 1 patient (Clavien Dindo 3a).

Conclusions: MiniPCNL using a SPTFL is a highly effective and safe treatment for patients with kidney stones 2 cm or larger.

MP05-17 Micro‐ureteroscopy for treatment of mid and upper ureteral stones and kidney stones in pediatric patients younger than 3 years

R Zhan, Y Ge, W Wang

beijing friendship hospital

Introduction & Objective: This study was aimed to demonstrate the efficacy and safety of micro‐ureteroscopy in the treatment of upper ureteral stones and kidney stones in pediatric patients younger than 3 years.

Methods: A retrospective analysis was performed on data from 25 children younger than 3 years old who received micro‐ureteroscopic lithotripsy in our hospital from July 2018 to June 2020. The procedures were performed with the patient in the lithotomy position under general anesthesia using the standard ureteroscopic technique with a micro‐ureterocope that has a caliber of 4.85 Fr all along its length. Demographics, perioperative data, including surgical time, irrigation fluid volume, stone‐free rate (SFR), and complications were analyzed.

Results: The patients' mean ages were 21.4 ± 9.7 months(9‐36months), 11 patients had ureteral stones; 12 patients had kidney stones, 2 patients had kidney and ureter stones. The mean stone size was 1.0 ± 0.2cm (0.6‐1.4cm). The mean stone density was 620 ± 192 HU(185‐982HU). Hydronephrosis was found in 21 patients. The mean surgical time was 43 ± 9 min (25‐60min), and the mean lithotripsy time was 18 ± 6 min (10‐30min); the mean irrigation fluid volume was 241 ± 134 ml (60‐610 ml), and the SFR at one month after surgery was 84%. As a postoperative complication fever (Clavien grade 1) was observed in two cases and required antibiotic treatment. MicroPCNL was needed in three patients with impacted stone in one case and with lower pole stones in two cases.

Conclusions: This study showed that micro‐ureteroscopic lithotripsy was safe and effective for mid and upper ureteral stones and kidney stones in selected pediatric patients under three years of age, however, the impacted ureter stone and the presence of lower pole stones will decrease the success rate of micro‐ureteroscopy.

MP05-18 Ambulatory Percutaneous Nephrolithotomy Performed in a Free‐Standing Surgery Center: Outcomes of 1000 Cases

MM Dunne, N Ariasvillela, JE Abbott, J Davalos

Chesapeake Urology, Univeristy of Maryland Baltimore Washington Medical Center

Introduction & Objective: Percutaneous Nephrolithotomy (PNL) is a procedure that has traditionally been performed in an inpatient setting with at least an overnight stay. Many surgical procedures have evolved over time from an inpatient setting to an ambulatory surgery center (ASC) setting. Feasibility of Ambulatory PNL (aPNL) was shown in our initial pilot series of 25 cases [1]. This 1000 case series is reviewed to further evaluate outcomes with a more robust data set.

Methods: We present our series of 1000 patients who underwent PNL in an ASC from April 2015 to January 2021. Each aPNL was performed by one of two surgeons with the same operative team. All procedures were performed with the urologist obtaining renal access and all procedures were performed tubeless (ureteral stent without a nephrostomy tube). All patients also had hemostatic plugs placed into the access tract with a local intercostal block to aid with pain control. [2] All cases were reviewed and demographic data and case details were analyzed.

Results: 1000 consecutive aPNL cases were reviewed, identifying 488 men and 512 women, 460 right side and 535 left, mean age 57 years (15‐86), mean BMI 30 (15‐49), mean ASA of 2.3 (1‐4) and mean stone burden 31 mm (4‐170), mean fluoroscopy time 84 sec (0‐322). Mean OR time was 95 min (32‐305) and mean treatment time was 14.9 min (1‐262). Mean PACU time was 91 min (37‐247). A mini‐PNL (mPNL) procedure was conducted in 255 (25.5%) patients. The remaining 745 cases were standard tract size of which 449 were 30Fr and 296 were 24Fr. Stone free rate was 83%. Thirty nine patients had complications ranging from Clavien II‐IVa, of which 15 were hospital transfers.

Conclusions: These consecutive 1000 cases may serve as a landmark series demonstrating the feasibility of aPNL. Transitioning PNL to an ambulatory setting is a paradigm shift in the treatment of complex kidney stones. 39 patients experienced complications of Clavien II or higher. Each complication that occurred was managed in an appropriate fashion and the site of service did not lead to an alteration in the outcomes of the adverse events. With an experienced surgeon, well trained operative team and with modifications to the procedure focusing on post‐operative pain control, PNL can be safely and effectively performed in a free standing ASC. 1. Davalos JG, Abbott JE. Ambulatory PCNL: Initial Case Series. J Urology. April 2016 2. Abbott JE, Cicic A, Jump R, Davalos JG. Hemostatic Plug: Novel Technique for Closure of Percutaneous Nephrostomy Tract. J Endourol. March 2015

MP05-19 Cost‐Analysis of Mini‐Percutaneous Nephrolithotomy (PCNL) and Standard Tract PCNL for Stone Burden Greater/Less Than 20 mm in an Ambulatory Setting

MM Dunne, J Chong, B Magnan, J Davalos

Chesapeake Urology, Univeristy of Maryland Baltimore Washington Medical Center

Introduction & Objective: Percutaneous Nephrolithotomy (PCNL) has traditionally been the standard of care for kidney stones >20 mm. With the advent of smaller instruments and efficiency of holmium laser technology, Mini‐PCNL (MIP, Karl Storz, Tuttlingen, Germany) which encompasses three sizes, (small, medium, and large) has become a viable option for stones between 10‐20 mm and has also demonstrated efficacy in stones >20 mm. MIP has been touted to have significant cost savings in direct‐items costs due to reusable dilator and sheath sets. The cost analysis of MIP in comparison to standard tract PCNL (sPCNL) has not previously been elucidated for various stone sizes.

Methods: All PCNL procedures (33 MIP and 61 sPCNL) performed at a single ambulatory surgery center from April 2019‐September 2019 were reviewed. All MIP tracts were MIP‐medium (16.5/17.5 French). sPCNL ranged from 24/28‐30/34 French. All dual‐tract procedures and patients needing transfer to hospital were excluded. Patient and stone characteristics such as age, sex, BMI, skin‐to‐stone distance, Hounsfield Units (HU) and operative characteristics such as operating room (OR) time, fluoroscopy time, intracorporeal (IC) time and total treatment (TT) time were compared between groups. Cost in US Dollars (USD) were separated into two categories, <20 mm and >20 mm, based on the surgical CPT codes 50080 vs. 50081 and compared between the MIP and sPCNL groups.

Results: here were no differences in sex, BMI, skin‐to‐stone distance or stone HU between groups. Patients having MIP tended to be younger (50.4 vs. 59.1, p = 0.0045) and have lower overall stone burden (17.73 mm vs. 33.38 mm) compared to sPCNL procedures. There were no differences between groups in regard to operative time characteristics. The direct‐items cost to patient was greater in sPCNL compared to MIP regardless of whether the stone treated was <20 mm ($1805.20 vs. $1382.42, p = 0.0087) or >20 mm ($1774.22 vs. $1293.31, p < 0.0001).

Conclusions: The reusable MIP‐medium single dilator and sheath 16.5/17.5 French combination has significant direct‐items cost savings to the patient compared to patients having sPCNL. The cost savings remain even if stone burden is greater than 20 mm. MIP can be offered as a cost‐saving procedure to the patient even up to 40 mm of stone burden.

MP05-20 Ambulatory PCNL may be cost‐effective compared to Standard PCNL

MS Lee, M Assmus, DK Agarwal, ME Rivera, T Large, AE Krambeck

Northwestern University Feinberg School of Medicine

Introduction & Objective: In March 2020, hospitals across America locked down to prevent the spread of COVID‐19. This resulted in catastrophic financial losses and massive surgical backlog. While multiple groups have shown that ambulatory percutaneous nephrolithotomy (aPCNL) is safe and feasible, to our knowledge, a cost‐analysis comparing aPCNL against standard PCNL (sPCNL) has not been performed. Prior to March 2020, our group was not performing routine aPCNL, but to conserve hospital resources, we performed aPCNL more often. Our objective was to compare the safety and cost‐effectiveness of sPCNL vs. aPCNL.

Methods: 98 patients underwent PCNL at Indiana University Methodist hospital, a tertiary referral center, by three expert surgeons from January 2020 to September 2020. sPCNL (n = 75) and aPCNL (n = 23). All patients had at least 30‐days of follow up. The primary outcome of the study was to compare the 30‐day rates of ED‐visits, readmissions, and complications between sPCNL and aPCNL. Secondary outcomes included: cost analysis and stone free rates (SFRs). Statistical analysis was performed using SPSSv26 using independent t‐tests for continuous variables and chi‐square analyses for categorical variables.

Results: We found no difference in 30‐day ED‐visits, readmissions, or complications between the two groups. aPCNL resulted in cost savings of $5689 ± 237 per case, a 29.6% reduction.

Conclusions: aPCNL appears safe to perform and does not have a higher rate of ED‐visits or readmissions compare to sPCNL. aPCNL also is also costeffective compared to sPCNL. Patients undergoing same‐day discharge were not at higher risk of ED‐visits or readmission to the hospital.

MP05-21 Economic Burden of Urolithiasis Management in United States Adults 2011‐2018: Analysis of Surgical vs. Non‐Surgical Interventions

E Olweny, A Becerra, JA Khusid, M Sturgis, L Fink, M Gupta, B Konety

Rush University Medical Center

Introduction & Objective: The United States (US) healthcare landscape has witnessed numerous changes over the past decade including population growth and implementation of the Affordable Care Act. Alongside these has been a rising prevalence of upper urinary tract stone disease (SD). Data on the economic burden of treating SD during this period are lacking, providing the objective of our study.

Methods: Patients aged ≥18 years, diagnosed with SD from 2011‐2018 (N = 838,113), were identified from PearlDiver Mariner, an all‐payer database reporting direct reimbursements and prescription costs across all treatment settings, representing all 50 states. Patients undergoing surgical intervention as well as those managed non‐operatively were identified via ICD 9/10 and CPT codes. Total 1‐year cost data in the year following SD diagnosis were obtained. Data were analyzed descriptively, with trends evaluated using the Cochran‐Armitage test. Multivariable analysis (MVA) was used to evaluate determinants of spending.

Results: A total of $10B were spent on SD management over the study period, with a median overall annual expenditure of $1.3B. Inpatient, prescription and outpatient costs accounted for 34.3%, 20.8% and 44.9% of expenditures respectively. 73% of patients were managed non‐operatively, at a total cost of $6.4B. Overall per capita cost was $11,971 ($15,981 for surgical vs. $10,503 for non‐surgical care). For surgical and non‐surgical management, expenditure on inpatient care decreased significantly over the study period, while expenditures on prescriptions and outpatient care increased significantly (each p < 0.0001). On MVA, higher Charlson comorbidity index (CCI) was associated with higher spending, while associations for age, insurance status and region varied by treatment modality.

Conclusions: The economic burden of SD management is substantial, dominated by expenditure on non‐operative management and outpatient care. Expenditures for prescription and outpatient care are rising, with the only consistent predictor of higher spending being CCI. Per capita expenditure exceeded US National Health Expenditure estimates for the period, driven by surgical costs.

MP05-22 Determinants of ureteral patency after percutaneous nephrolithotomy

H Lee, H Yang, R Unno, F Hamouche, J Ahn, D Bayne, M Stoller, T Chi

Introduction & Objective: Alleviating ureteral obstruction is one of the primary indications for nephrostomy tube or double‐J stent placement after percutaneous nephrolithotomy (PCNL), but it is not well understood how to recognize when tube placement is needed. The goal of this study was to identify predictors of ureteral obstruction after PCNL based on antegrade studies performed on postoperative day one (POD1).

Methods: Prospective data from PCNLs was collected from adult patients enrolled in the Registry for Stones of the Kidney and Ureter (ReSKU) from 2016‐2020. Patients who had postoperative nephrostomy tubes and underwent antegrade imaging‐based flow assessment on POD1 were included. Patients without preoperative imaging within 6 months of the procedure or who had transplanted kidneys were excluded. We assessed patient demographics, stone characteristics, and intraoperative factors, using POD1 antegrade flow as the primary outcome. Forward selection was used to develop a multivariate logistic regression model controlling for age, staghorn classification, stone location, stone burden, number of dilated tracts, access location, and operative time.

Results: A total of 242 patients were included in the study, of which 77 patients had no antegrade flow on POD1. A multivariate logistic regression showed that non‐renal pelvis stones (OR 2.44, 95% CI 1.19‐5.19; p = 0.02), larger stone burden (OR 1.23, 95% CI 1.05‐1.48; p = 0.01), and mid/upper pole access during surgery (OR 3.52, 95% CI 1.74‐7.45; p < 0.01) increased the likelihood of obstruction. The presence of staghorn stones, use of concurrent multiple tracts, and operative time were not significant predictors of antegrade flow in our model.

Conclusions: Patients who had non‐renal pelvis stones, a larger stone burden, and non‐lower pole access were more likely to have postoperative ureteral obstruction. Access location appears to be the strongest predictor. Recognizing these risk factors can help determine which patients may benefit from renal drainage tubes after surgery or which patients may be good candidates for tubeless PCNL.

MP06-01 Resolution of Hydronephrosis and Pain to Predict Stone Passage for Patients with Acute Renal Colic: Analysis from the STONE trial

S Jackman, A Maganty, A Wolfson, P Burrows, C MacPherson, N Montano, Z Kirkali, A Meltzer

UPMC

Introduction & Objective: To study patients presenting to the Emergency Department with acute renal colic to determine if resolution of hydronephrosis and pain accurately predicts stone passage on follow‐up CT.

Methods: This is a secondary analysis of a multi‐center prospective randomized clinical trial of patients diagnosed by computed tomography (CT) scan with a symptomatic ureteral stone <9 mm in diameter. Participants were followed to evaluate for analgesic use and to assess stone passage and hydronephrosis on a repeat CT scan obtained at 29‐36 days.

Results: Four‐hundred‐three patients were randomized in the original study and patients were included in this analysis if they did not have surgery for stone removal and had a CT scan and information on pain medication at follow‐up (N = 220). Hydronephrosis was detected in 181 (82%) on initial CT. At follow‐up CT, 43 (19.5%) participants had a persistent ureteral stone. Of these participants, 36 (84%) had no pain, 26 (60%) did not have hydronephrosis and 23 (53%) had neither pain nor hydronephrosis. Resolution of hydronephrosis was associated with stone passage (RR 4.6, 95% CI 1.9, 11.0), while resolution of pain was not (RR 1.1, 95% CI 0.9, 1.4).

Conclusions: In patients with urinary stone disease, stone passage is associated with resolution of hydronephrosis but not resolution of pain. In patients with persistent ureteral stones, neither pain nor hydronephrosis are consistently present. These findings have important implications on follow‐up imaging of patients with urinary stone disease.

MP06-02 Visual clarity of irrigants used during flexible ureterorenoscopy: an in vitro comparison

V Ulker, Z Gulerce, O Celik, C Yucel, E Can, B Turna

Department of Urology, University of Health Sciences Izmir Tepecik Training and Research Hospital

Introduction & Objective: Saline solution is the standard irrigant used during flexible ureteroscopy (f‐URS). However, there is an opinion that water has better visual clarity. Obtaining optimal image quality is quite important during f‐URS with fiberoptic devices, since suboptimal image quality may interfere with the efficacy of the procedure. In this in vitro study, we aimed to compare the visual clarity of isotonic saline, distilled water, and additionally 5% mannitol as irrigants for f‐URS.

Methods: An in vitro model consisting of an irrigant‐filled container and a fiberoptic f‐URS (Karl Storz Flex x^2S ) was designed. A 1951 USAF Resolution Test Target (3x3 inch) within irrigants were used to evaluate the clarity of vision. The visual clarity was compared for 0.9% saline, distilled water and 5% mannitol solution by evaluaters with screen resolution. The tests were repeated after adding human blood (2/400 ml) and contrast (20/400 ml) to the irrigants.

Results: There was no significant difference in resolution values of three plain irrigants at a distance of 10 mm. However, when blood was added to the irrigants, a better resolution of 29.3% for water and 20.6% for mannitol was achieved compared to saline. At 20 mm of distance, it was observed that the difference was more pronounced in irrigants with blood. Water and mannitol had 55.6% and 37.1% better resolution than saline, respectively.

Conclusions: Water and 5% mannitol did not provide a significant image clarity advantage compared to saline. However, when blood was added to the irrigants, water provided significantly better visual clarity compared to saline. The use of water during various clinical scenarios in f‐URS should be further investigated.

MP06-03 Chloroquine attenuates hyperoxaluria‐induced renal oxidative injury and calcium oxalate crystal depositions via inhibiting NADPH oxidases

X Duan, S Yin, Y Liu, G Zeng

Introduction & Objective: Our previous study had indicated that chloroquine could attenuate hyperoxaluria‐induced oxidative injury of renal tubule cells, as well as calcium oxalate (CaOx) crystal depositions in rat kidney, but its underlying mechanism still has not been fully clarified. This study was carried out to reveal its possible underlying mechanism.

Methods: Sprague‐Dawley rats were randomly divided into three groups: control group, ethylene glycol‐induced hyperoxaluria model group and the model group pretreated with chloroquine. The renal CaOx crystal depositions were detected using Pizzolato staining method. The expressions of NADPH oxidases in rat kidney were detected via using real‐time qPCR and immunohistochemical staining. For the cell experiments, the expression and phosphorylation of PKCα and PKCδ, as well as NADPH oxidases' expressions, were detected by western blot, whereas the role of PKCs (including PKCα and PKCδ) in chloroquine‐mediated NADPH oxidases' expressions was confirmed though using PKC activator PMA in NRK‐52E cells.

Results: Chloroquine significantly decreased the mRNA and protein expressions of NADPH oxidases, including NOX2 and NOX4, as well as NADPH oxidase‐mediated oxidative injury of renal tubular cells in vivo and in vitro. In addition, chloroquine could attenuate oxalate‐induced phosphorylation of PKCα and PKCδ, whereas PKC activator PMA could obviously reverse the effects of chloroquine on oxalate‐induced oxidative injury of NRK‐52E cells and NADPH oxidases' expressions.

Conclusions: Chloroquine could significantly attenuate oxalate‐induced oxidative injury of renal tubular cells in vitro and in vivo, as well as hyperoxaluria‐induced CaOx crystal depositions in rat kidney, at least in part, via inhibiting PKC‐mediated expressions of NADPH oxidases, thus suggesting a novel possible application of chloroquine for the clinical prevention and management of CaOx nephrolithiasis.

MP06-04 Automatic computer‐aided in‐situ recognition of morphological features of pure and mixed urinary stones using intraoperative endoscopic images

V Estrade, m Daudon, f Bladou, j Bernhard, G Robert, B Denis De Senneville

Chu Pellegrin

Introduction & Objective: Endoscopic Stone Recognition (ESR) provides essential observations of stone morphologies. Artificial intelligence (AI) algorithms applied to various types of microscopic images of stones ex‐vivo proved to be a promising asset for automatic ESR using both peri‐ and post‐operative images [1]. In this study, we report the preliminary results of the automatic ESR of the morphological components of both pure and mixed urinary stones..

Methods: A urologist (VE, 20 years of experience) prospectively examined per‐operative endoscopic digital images of stones acquired between January 2018 and November 2020 (single‐center) using a flexible digital ureterorenoscope (Olympus URF‐V CCD sensor). Morphological criteria were collected and classified according to recommendations outlined in [2]. A deep convolutional neural network (CNN), ResNet‐152‐V2, was trained to predict five morphology classes from images obtained before LASER fragmentation: three pure stones (Ia/COM, IIb/COD and IIIb/UA) and two mixed stones divided into two morphologies (Ia/COM+IIb/COD and Ia/COM+IIIb/UA).

Results: The study included 347 observations of stone surface (pure stones: Ia = 191, IIb = 53, IIIb = 29; mixed stones: Ia+IIb = 64, Ia+IIIb = 10). Table 1 provides the performance of the implemented CNN classifier. In average, the accuracy was higher than 87 % for both pure and mixed stones.

Conclusions: AI is a good candidate for the automatic ESR of the morphological features of pure and mixed urinary stones composed of two morphologies. Combined with didactic boards of confirmed endoscopic images, both computer‐aided diagnosis and associated activation maps may be useful for urologists to recognise stones in‐situ using an endoscopic examination before destruction.

[1] Black et al. BJUI 2020, 125(6):920‐924

[2] Estrade et al. BJUI 2020, 10.1111/bju.15312

MP06-05 Postoperative Urinary Tract Infections After Flexible Ureteroscopy Using High‐Level Disinfection With 2 % Glutaraldehide for Flexible Scopes

P Alarcon, E Flores, EE Lozada, S Hector, BO Manzo

Hospital Regional de Alta Especialidad del Bajío

Introduction & Objective: Objective To describe the urinary tract infection incidence in flexible ureteroscopy using reusable scopes subjected to disinfection with 2% Glutaraldehyde.

Methods: Patients and Methods A cross‐sectional retrospective study was carried out. 347 patients treated with flexible ureteroscopy for lithiasis treatment were identified, and data was collected. The 2% Glutaraldehyde was used to disinfect the scopes in all surgeries. Disinfection protocol took 20 min. We included preoperative, intraoperative, and postoperative variables in statistical analysis. The SPSS statistics program was used for the statistical analysis. All variables were subjected to a normality test and subsequently Chi‐square. Fisher's exact test, Student's T‐test, or Mann Withney's U were applied, depending on the type of variable.

Results: A total of 233 patients met inclusion criteria and had complete data. An incidence of urinary tract infections of 8.5% was encountered. The side affected and gender was similar between infected and not infected patients (p = 0.614, and p = 0.109, respectively). There was a difference in age and BMI between the infected and not infected patients (p = 0.019 and p = 0.046). Schemes and antibiotic agents for prophylaxis were equally given between infected and non‐infected patients (p = 0.847). Other relevant variables like patients' comorbidities, stone burden, positive preoperative urine culture, or surgical time were not statistically significant (p > 0.05). The two most frequently isolated germs were Pseudomonas Aeruginosa and Escherichia coli, with five patients in each group. We obtained a negative urine culture in 4 patients (20%).

Conclusions: After flexible ureteroscopy with reusable ureteroscopes disinfected with 2% Glutaraldehyde, the urinary tract infection has an acceptable incidence. Moreover, similar to the incidence previously reported in the worldwide literature. The two most common germs isolated were Pseudomonas Aeruginosa and Escherichia coli.

MP06-06 A critical assessment of digital single‐use flexible ureteroscopes in a porcine model

SK Bechis, B Eisner, BR Matlaga, O Shah

University of California ‐ San Diego, Department of Urology

Introduction & Objective: Following the introduction of the digital single‐use flexible ureteroscope several years ago, an increasing number of products have come to the market. Each of these scopes has unique attributes that can affect their functionality. We undertook a study to characterize the performance of presently available digital single‐use flexible ureteroscopes in a porcine model.

Methods: Four female pigs (50‐60kg) were placed under general anesthesia, positioned supine, and retrograde access to the renal collecting system was obtained. The LithoVue^™ (Boston Scientific), EU‐Scope (AnQing Medical; available in the US as Dornier Axis^™), and WiScope^® (OTU Medical) were each evaluated by four experienced surgeons. The following parameters were assessed quantitatively: time for navigation to the upper and lower pole calyces with and without implements (1.9F basket, 200 μm laser fiber, and 365 μm laser fiber). A qualitative rating (scale 1‐5) assessed: handle ergonomics, irrigation flow, image quality, and scope maneuverability. ANOVA statistical analysis was performed for comparisons among the groups, with statistical significance established at p < 0.05.

Results: The qualitative metrics included both baseline and last pass image quality ratings, which were significantly better for LithoVue than the AnQing and WiScope devices. Similarly, both baseline and last pass access metrics were also significantly better for LithoVue. The quantitative time measurements were not significantly different among the scopes when the upper pole was accessed with an empty working channel, 1.9F basket, and 200 μm laser fiber and when the lower pole was accessed with a 1.9F basket. Time measurements significantly favored the LithoVue for the remainder of the tests. Qualitative ratings significantly favored AnQing for upper and lower pole access with the 365 μm fiber. The remainder of the qualitative ratings related to navigation significantly favored LithoVue with the exception of empty working channel navigation to the upper and lower poles, which were not significantly different among the scopes. The comparisons are presented in the Table.

Conclusions: This study represents the first in vitro comparison of single‐use ureteroscopes from multiple vendors. In this study, the LithoVue performed significantly better than the AnQing and WiScope products. Further studies in clinical practice will provide additional information that will enable surgeons to distinguish the performance characteristics of these devices.

MP06-07 Predictive factors for ureteric stricture formation after ureteroscopic treatment of impacted ureteric stones

M Ramachandra, Z Al‐Nabulsi, Y Phan, P Osborn, A Auer, C Rowbotham, M Ismail

University Hospital Southampton, UK

Introduction & Objective: Introduction Ureteric stricture is a potential complication of impacted ureteric stone. In this study we investigated predicting factors of stricture formation after ureteroscopy for impacted ureteric stone

Methods: Surgical and radiological data for patient who underwent ureteroscopy for impacted ureteric stone were retrospectively reviewed.

Results: Between 2014 and 2019, 1340 patient presented with renal colic secondary to ureteric stone. A total of 297 ureteroscopy procedures were performed for impacted stones. Stricture rate was 3.3%. Analysis of radiological and surgical factors revealed that degree of hydronephrosis, intraoperative ureteric injury and residual stone fragments are statistically significant predicting factors for ureteric stricture formation.

Conclusions: Rate of stricture formation following ureteroscopic treatment of impacted ureteric stone remains low. Ureteric stricture may be a silent disease and can present with renal impairment. Therefore, it is essential to arrange postoperative imaging for high risk patients.

MP06-08 Prospective randomized comparison of classical retroperitoneoscopic pyelolithotomy versus percutaneous nephrolithotomy for solitary large pelvic kidney stones

V Singh, RJ Sinha, G Singh

Dept of urology, King George Medical University

Introduction & Objective: Percutaneous nephrolithotomy (PCNL) can be difficult in large pelvic stones in undilated systems. Retroperitoneoscopic pyelolithotomy can a feasible treatment option in these cases. We performed a prospective randomized comparison of retroperitoneoscopic pyelolithotomy (RP) versus percutaneous nephrolithotomy (PNL) for solitary pelvic stones >3 cm and assessed the outcome results.

Methods: From 2016 to 2019, 44 patients with a solitary pelvic stone >3 cm without any anatomical abnormality were randomized to either RP or PNL on a 1: 1 ratio. Stone‐free rate, number of procedures per patient and complications were recorded.

Results: The stone‐free rate on the first postoperative day was 95.5% in the RP group versus 72.7% in the PNL group (p = 0.04). The stone‐free rates at 3 months were similar between the two groups. Blood loss, visual pain analog score and analgesic requirement on the first postoperative day were significantly higher in the PNL group whereas the mean operative time and overall complications were similar between the two groups.

Conclusions: In patients with solitary large pelvic stones, RP is associated with lesser blood loss, postoperative pain and analgesic requirement as well as with a higher stone‐free rate in the immediate postoperative period in comparison to PNL. However, the stone clearance rate remains the same at 3 months in both groups.

MP06-09 Endoscopic Combined Intrarenal Surgery (ECIRS) – The new standard in the treatment of complex stone disease?

J Correia, M Madanelo, B Teixeira, G Mendes, S Mesquita, A Fraga, M Silva‐Ramos, V Cavadas

Department of Urology, Centro Hospitalar Universitário do Porto

Introduction & Objective: Percutaneous nephrolithotomy (PCNL) is currently the gold standard in the treatment of large urolithiasis. Although it is a safe and effective technique, it is still associated with important complications. Endoscopic Combined Intrarenal Surgery (ECIRS) combines the simultaneous approach of PCNL with retrograde URS, with the objective of treatment in a single procedure, reducing radiation exposure, complications and renal damage associated to PCNL. We aimed to evaluate the safety and efficacy of ECIRS in the treatment of high stone burden.

Methods: We performed a retrospective analysis of perioperative data and complications of all 148 patients submitted to ECIRS at our institution between January 2017 and November 2020. All surgeries were performed in modified supine Valdivia position. Stone free rate (SFR), defined as ≤3mm size, was evaluated by CT scan at 3 months.

Results: Patient's mean age was 52 ± 14 years, the majority of them females (72%). 16 had anatomical anomalies (11%), 5 had solitary kidney (3%) and 2 an urinary diversion with cutaneous ureterostomy (1%). 36 were previously stented with JJ (24%). Mean stone size was 38mm [IQR 31‐554], with a density of 819 ± 291 HU. The majority of patients had multiple or staghorn stones (73%), 6 of them being operated bilaterally (4%). Mean operative time was 128 ± 40min, using mainly pneumatic (70%) and LASER (15%) lithotripsy. 80% of the procedures used a single access (n = 118); the working sheath most commonly used was 17,5Fr (80%). Postoperative nephrostomy was placed solely in 24% of the patients during a median of 2 days [IQR 2‐4]. 1 of the procedures was totally tubeless. Median of hospital stay was 3 days [IQR 2‐3]. SFR was 65%, but only 9% needed a second procedure. There was a significant association between SFR and stone size (p = 0,034) but not its location (p = 0,70). The most common complication was transient fever promptly responsive to antibiotic (n = 25, 17%), and only 2 patients had complication grade ≥3 (arteriovenous fistula requiring embolization). Mean haemoglobin drop was 1,3gr/dL [0,6‐2,4], with only 6 patients needing blood transfusion (4%). None of the analysed variables (sex, BMI, diabetes, previous JJ, structural anomalies, struvite stones, location and number of accesses, surgery time and stone size) was associated with the occurrence of post‐operative complications.

Conclusions: ECIRS is a safe and effective procedure, offering an additional option for patients with multiple and complex lithiasis. Although in our analysis SFR was inferior to the described in the literature, stone size and his complexity were superior to previous reports, yet maintaining a low rate of complications.

MP06-10 A preoperative predictive score for uric acid kidney stones

MJ Basulto‐Martínez, S Proietti, M Pavia, L Rico, Y Yeow, J Flores‐Tapia, A Esqueda‐Mendoza, F Gaboardi, G Giusti

Dept. of Urology, Hospital Regional de Alta Especialidad de la Península de Yucatán

Introduction & Objective: Uric acid calculi (UAC) account for up to 15%. Recent evidence points that UAC <2 cm can be first treated by alkalinizing therapy with good results. Furthermore, alkalinizing larger UAC, may decrease the stone burden and therefore improve the chance of achieving a stone‐free rate in a further surgical procedure. We aimed to create a preoperative score for predicting UAC.

Methods: Patients who underwent kidney stones surgery from to March 2018 to March 2019 with available preoperative abdominal non‐contrast computed tomography (CT) scan and stone analysis composition were included and clinical data was obtained. Mean Hounsfield Units (HU) and standard deviation from the stone density (SDSD) were calculated from CT scans, as computed by growing Regions of Interest using OsiriX DICOM viewer Software. The stone analysis composition was carried out by infrared spectroscopy. Stones >80% of uric acid were dichotomized as UAC or otherwise as non‐uric acid calculi (NUAC). Categorical data were compared by X2 test, continuous data by the U‐Mann‐Whitney test, and logistic regression test was performed for categorical data and UAC. ROC curve analysis was conducted for the HU, SDSD, and UAC, and cutoff points were set. Using data associated with UAC, a score was constructed and tested.

Results: Ninety‐two patients were included with a median age of 55 (46 – 65) years and 53.3% were female. The stone composition was 67% calcium‐containing, 14% uric acid, 10 % infective, 7.7% cystine, and 1% other stones. HU was significantly lower in UAC group [400 (304 – 565) vs 689 (521 – 689), p < 0.001] as well as SDSD [152.2 (125.9 – 319.4) vs 358.1 (267.6 – 446.5), p < 0.001]. T2D and HTN were associated with UAC (p = 0.007 and p = 0.041, respectively) ROC curves for UAC and mean HU showed an area under the curve (AUC) of 0.851, [Coefficient Interval (CI) 95% 0.73 – 0.97], p < 0.001. As for SDSD, AUC was 0.808 (CI95%, 0.67 – 0.94). Cutoff points were selected according to the best specificity and sensitivity. Thus, a score ranging from 0‐4 was created based upon variables significantly related to UAC, which were HTN, T2D, mean HU <400, and SDSD <350. Score of 0, 1, 2, 3, and 4, resulted in UAC proportion of 0%, 6.7%, 25%, 66.7%, and 100%. The AUC for the score was 0.86 (CI 95% 0.77 – 0.96) p < 0.001. Patients with a score of 3‐4 had 71.4% of UAC (p < 0.001)

Conclusions: This easy‐to‐use preoperative score is useful in detecting patients who might have UAC and a better selection for an alkalinizing therapy can be performed. A score of 3‐4 is a powerful predictor of UAC and adds to clinical decision‐making for alkalizing therapy.

MP06-11 Pattern of key opinion leaders talks at major international urological meetings reflect the main differences in flexible ureteroscopy and PCNL diffusion

E Ventimiglia, F Quadrini, F Pauchard, H Kamkoum, S Doizi, O Traxer

Division of Experimental Oncology/Unit of Urology; URI; IRCCS Ospedale San Raffaele

Introduction & Objective: To analyze the pattern of speaker activity related to both flexible ureteroscopy (fURS) and percutaneous nephrolithotomy (PCNL) during plenary sessions at the main (endo)urological international meetings over the last 10 years.

Methods: We retrospectively reviewed the meeting programs of the main endourological international meetings (EAU, AUA, WCE, and SIU) during the period 2011‐2019. We detected all invited speakers at plenary and thematic sessions discussing either fURS or PCNL and collected both name and age at presentation. The proportion of fURS and PCNL talks was evaluated yearly during the study period. In order to analyze the variety of plenary session composition in terms of different panelists, we estimated and compared the mean number of talks per speaker according to surgical technique. We also analyzed possible differences in age distribution according to the topic of the talk as well as the presence of young (i.e. <45 years) speakers. Data were analyzed using descriptive statistics.

Results: During the last 10 years, a total of 498 plenary talks were found. Of those, 260 (52.2%), 211 (42.4%), and 27 (5.4%) discussed PCNL, fURS, or both respectively. The relative proportions of fURS vs PCNL changed during the last 10 years, with PCNL being more frequently discussed at the beginning and the end of the study period. Mean [SD] number of talks per speaker was higher for PCNL speakers (2.9 [3.4] vs 1.6 [1.4], p < 0.001), meaning that a wider variety of speakers was invited to give fURS talks. Speakers discussing fURS were younger (mean [SD] age 51 [9.5] vs 54 [8.5] years, p < 0.001), and a higher proportion of young speakers was observed in the fURS group (26% vs 15% p < 0.001). PCNL speakers were more commonly discussing fURS than fURS speaker discussing PCNL (23% vs 17%, p = 0.43).

Conclusions: We found a wider variety of speakers at fURS plenary sessions as compared to PCNL ones. Age at presentation was lower for fURS speakers, and a higher proportion of young experts was able to be invited to give a plenary talk. These data suggest that it is easier and quicker to become an internationally recognized expert in the field of fURS rather than PCNL. Moreover, PCNL speakers were able to master fURS as well more frequently than the other way around.

MP06-12 Withdrawn

MP06-13 Natural history of small asymptomatic kidney and residual stones over a long‐term follow‐up: Systematic review over 25 years

CE Lovegrove, R Geraghty, B Yang, E Brain, SA Howles, BW Turney, BK Somani

Department of Urology, Oxford University Hospitals NHS Foundation Trust; Nuffield Department of Surgical Sciences, University of Oxford

Introduction & Objective: Incidental identification of small, asymptomatic renal calculi has risen with increasing high‐resolution imaging. The natural history of such stones and small residual fragments remains unclear, however kidney stone disease (KSD) demands growing healthcare resource utilisation with wide‐ranging costs of treatment and varying management recommendations.

Methods: We systematically reviewed the natural history of small asymptomatic kidney and residual stones using the Cochrane and PRISMA methodology. We searched Medline, Scopus, Embase, EBSCO, Cochrane library and Clinicaltrials.gov using themes of “asymptomatic”, “nephrolithiasis”, “observation”, “symptoms”, “admission”, “intervention” and similar allied terms for all English language articles from 1996‐2020 (25 years). Inclusion criteria were studies of minimum 50 patients, stones ≤10mm, and mean follow‐up of ≥24 months. Primary outcomes were occurrence of symptoms, emergency admission and intervention.

Results: Our literature search returned 2247 results of which 10 papers were included in the final review. Risk of symptomatic episodes ranged from 0‐59.4%. Meta‐analysis did not identify any significant difference in the likelihood of developing symptoms when comparing stones <5mm to those >5mm, nor those <10mm to those >10mm. Risk of admission varied from 14‐19% and risk of intervention from 12‐32%. Meta‐analysis demonstrated significantly decreased likelihood of intervention for stones <5mm vs. >5mm and <10mm vs. >10mm. Studies had variable risk of bias due to heterogeneous reporting of outcome measures with significant likelihood that observed differences in results were compatible with chance alone (Symptoms: I² = 0%, Cochran's Q = 3.09, P = 0.69; Intervention: I² = 0%, Cochran's Q = 1.76, P = 0.88).

Conclusions: This systematic review indicates that stone size is not a reliable predictor of symptoms, however risk of intervention is greater for stones <5mm vs >5mm and <10mm vs >10mm. This review will inform urologists as they discuss management strategies with patients who have asymptomatic renal stones and offer insight to committees during the development of evidence‐based guidelines.

MP06-14 The T‐Tilt Position: a Novel Modified Patient Position to Improve Stone‐Free Rates in Retrograde Intrarenal Surgery

C Liaw, JA Khusid, B Gallante, JN Bamberger, WM Atallah, M Gupta

Icahn School of Medicine at Mount Sinai

Introduction & Objective: Residual fragments following retrograde intrarenal surgery (RIRS) can lead to future symptomatic stone episodes. The lower pole of the kidney presents a unique challenge as it is the most difficult location for RIRS. The T‐Tilt position is a novel modified patient position for RIRS in which the patient is positioned 15˚ Trendelenburg and 15˚ airplane away from the surgical‐side kidney (Figure 1). We investigated the efficacy of the T‐Tilt position in improving stone‐free rate (SFR).

Methods: In this IRB‐approved, prospective, randomized study, we recruited adult patients undergoing RIRS for stone removal. Patients were excluded if they had kidney abnormalities, pre‐existing ureteral stents, or a medical contraindication to the T‐Tilt position (e.g. congestive heart failure). Patients were preoperatively randomized to the standard or T‐Tilt position. Demographics, comorbidities, and operative parameters were recorded. SFR was determined with renal ultrasound and x‐ray at 1‐month follow‐up by a urologist blinded to the patient's study group. All complications, ER visits, and secondary procedures were recorded. Variables were compared using Kurskal‐Wallis test for continuous variables and chi‐square test for categorical variables.

Results: A total of 138 patients were enrolled with 75 patients in the standard cohort and 63 patients in the T‐Tilt cohort. The groups had similar patient demographic, clinical, and stone factors. The most common stone position was the lower pole (68.0% standard, 74.6% T‐Tilt). SFR was significantly greater in the T‐Tilt cohort amongst all patients (92.1% in T‐Tilt vs. 76.7% in standard, p = 0.015) and on sub‐analysis of patients with lower pole stones (95.6% in T‐Tilt vs 68.2% in standard, p < 0.001). There were no significant differences in operative times or Clavien‐Dindo scores.

Conclusions: The T‐Tilt position was associated with higher SFR. It is an atraumatic, cost‐effective technique in RIRS which may improve SFR and prevent future stone episodes.

MP06-15 Stone clearance using the EMS Swiss LithoClast^® Trilogy: results of the European multicentre prospective study in comparison to the BAUS national PCNL outcomes on behalf of the European Society of UroTechnology

N Thakare, F Tanse, K Saeb‐Parsy, N Atassi, R Endriss, G Kamphuis, D Perez‐Fentes, M Hasan, M Brehmer, PJ Osther, HU Jung, BW Turney, W Finch, N Burgess, S Irving, L Dragos, E Liatsikos, T Knoll, V Cauni, O Wiseman

Cambridge University Hospitals Nhs Trust

Introduction & Objective: The EMS Swiss LithoClast^® Trilogy is the latest generation lithotrite for PCNL, with a high clearance efficiency and faster stone fragmentation ability. The safety and efficacy of Trilogy has been evaluated in a prospective European multicentre study. We aim to assess the stone clearance rates in comparison to the BAUS PCNL audit outcomes obtained prior to the introduction of Trilogy.

Methods: 10 European centres evaluated the LithoClast^® Trilogy, in a prospective non‐randomized study from 2019 to 2020. Data including stone characteristics, PCNL technique and stone clearance at the end of the procedure were recorded. Analysis was undertaken to determine the stone clearance rates with respect to stone size and stone complexity categorised by Guy's stone scores (I – IV). The findings were compared to the outcomes from the BAUS national PCNL audit data (2016 ‐ 2019), whose contributors used a variety of different lithotrites, other than Trilogy. Statistical analyses were performed using the Chi‐square test.

Results: 157 patients undergoing PCNL using Trilogy were included (53% male, 47% female; mean age 55 years, range 13 ‐ 84 years). The overall stone free rate on fluoroscopy screening at the end of the procedure was 82.8% [BAUS: n = 7431; overall stone free rate = 79.4% (p = 0.23)]. Stone clearance for sizes = < 2cm and >2cm were 90.7% and 78.6% respectively compared to 88.9% and 74.5% respectively for BAUS audit (p > 0.05). The clearance rates for Guy's stone score I, II, III and IV were 89%, 97%, 84% and 65% respectively, compared to 95.6%, 86.3%, 75.5% and 51.9% reported by BAUS (p > 0.05). The results are summarised in Table 1.

Conclusions: Our results demonstrate that when stratified according to stone size and stone complexity, the clearance rates for LithoClast^® Trilogy are at least as effective as the outcomes reported from the prospective BAUS national database. None of the results reached a statistical significance, possibly due to low numbers in the Trilogy cohort. However, there is an indication that Trilogy could be a more efficient lithotrite in terms of stone clearance. These findings should be further evaluated, using clearance rates for stone size and complexity score in prospective studies for PCNL.

MP06-16 Long‐Term Evaluation of the Endockscope System: An Assessment of Global Usage

AS Afyouni, M O'Leary, Z Okhunov, A Peta, A Brevik, M Ayad, R Yoon, RM Patel, B Dolan, J Landman, RV Clayman

Department of Urology, University of California, Irvine

Introduction & Objective: The high costs of cutting‐edge endoscopic light sources and cameras restrict urologists from performing endoscopy in many underserved countries. Given the global prevalence of smartphones, we engineered a $45 smartphone alternative utilizing three‐dimensional (3D) printed attachments, an 8x lens, and a 1,000‐lumen light‐emitting diode (LED) cordless flashlight (the Endockscope System, ES).

Methods: Forty complimentary ES kits were distributed to urologists from 23 countries at the 2019 Congress of Société Internationale d'Urologie (8‐month group) and at the 2016 World Congress of Endourology (4‐year group) (Figure 1). Each participant was trained to use the ES. Urologists given an ES were asked to complete a survey in June 2020; the survey included questions regarding user satisfaction, comparability of the ES to standard endoscopic systems, and ease of use.

Results: All 18 urologists (100%) in the 8‐month group and 10/22 urologists (45%) in the 4‐year group completed the questionnaire. The ES was utilized by 83% (15/18) of urologists in the 8‐month group and by 80% (8/10) of urologists in the 4‐year group. Among urologists who used the ES, 67% in the 8‐month group and 57% in the 4‐year group noted that the ES performed equal or better than their standard endoscopic equipment. Using the human development index (HDI), a holistic measure of living standards across life expectancy, education, and the GDP per capita, we determined that the greatest impact was among urologists from the most fiscally challenged countries; indeed, in the 8 month and 4‐year groups, 100% of urologists from these countries were using the ES system. (Table 1) Lastly, although developed for fiberoptic cystoscopy, participants also used the ES for rigid cystoscopy, rigid and flexible ureteroscopy, and laparoscopy.

Conclusions: The ES provided an effective and inexpensive substitute for the standard high powered light source and endoscopic camera system at a cost of only $45. It was uniformly adapted by urologists in resource‐challenged countries.

MP06-17 Benchtop Assessment of a New Single‐Use Flexible Ureteroscope

P Whelan, RS Terry, R Qi, C Tabib, F Soto‐Paulo, GM Preminger, M Lipkin

Duke University

Introduction & Objective: Single‐use flexible ureteroscopes are an increasingly popular alternative to reusable ureteroscopes. In this study, we examined physical and optical properties of the new Dornier Axis^™ (Webling, Germany) single‐use ureteroscope.

Methods: Ten new, never‐used Dornier Axis^™ ureteroscopes were assessed for maximal tip deflection and irrigation flow rate with empty working channel and with insertion of a 200μm Flexiva^™ (Boston Scientific, Marlborough, MA), 200μm and 365μm Moses^™ (Lumenis, Yokneam, Israel) laser fibers and a 1.9Fr Zero Tip^™ (Boston Scientific, Marlborough, MA) nitinol basket in the working channel. All ureteroscopes were then fully deflected 100 times in each direction, and maximal deflection angles were re‐measured. All measurements were performed in duplicate. In‐vitro optical testing for resolution, image distortion, and depth of field was performed against the LithoVue^™ (Boston Scientific, Marlborough, MA) ureteroscope. Statistical analyses using t‐test and ANOVA were performed in R.

Results: Mean maximal deflection angles exceeded 300 degrees in both directions before and after 100 full deflection cycles except for the 365μm group. There was no change in maximal deflection following the 100 deflection cycles. There was difference in flexion with the various instruments in the working channel with the 365μm Moses^™ fiber having the lowest flexion (downward flexion 293.3°, p < 0.002) (Figure 1).

Mean flow rate through an empty channel was 46.7 ml/min and decreased significantly with all used instruments (p < 0.001) (Figure 1).

Compared to the LithoVue^™, the Axis^™ demonstrated superior resolution at all tested distances and less distortion (‐6.59 ± 4.24% vs ‐19.72 ± 10.81%, p = 0.028) (Figure 2). The LithoVue demonstrated superior depth of field (Dornier vs Lithovue 4.5cm (IQR 4.3 ‐ 4.5 cm) vs 5.0cm (IQR = 5.0 ‐ 5.0cm) at 15 line‐pairs/mm, p = 0.014).

Conclusions: The Dornier Axis^™ single‐use ureteroscope demonstrates high deflection angles that remain unchanged after 100 manual flexions in each direction and superior optical resolution compared to the LithoVue^™

MP06-18 Novel Image Quality Evaluation Tool for Ureteroscopes: Validation Study Using Four Widely Available Digital Ureteroscopes

SN Patel, RK Jain, AT Cranwell, S Quarrier

University of Rochester

Introduction & Objective: We sought to compare the image quality of three single‐use ureteroscopes (Boston Scientific LithoVue, Dornier Axis, Pusen Uscope; all use CMOS sensors) to a standard digital reusable ureteroscope (Olympus URF‐V2; uses CCD sensor).

Methods: We recorded video from several ureteroscopy cases using each ureteroscope. A representative 1 minute clip of one case with each scope was created. Blinded urology attendings (n = 5) and residents (n = 5) rated image resolution, contrast, color, sharpness, glare, depth perception, distortion/artifacts, and overall image quality on a 5 point Likert scale using a novel evaluation instrument. Internal consistency was tested and MANOVA was used to compare responses.

Results: Forty surveys were completed. The results demonstrated internal consistency (Cronbach α = 0.95). The domain most correlated with overall image quality was image resolution (0.71). Overall image quality, image resolution and contrast were rated higher in the Olympus than the LithoVue while the Uscope was rated lower than other scopes; sharpness was higher in the URF‐V2 than other scopes; color, glare, depth perception, and distortion/artifacts were better in the URF‐V2 than the Uscope (all p < 0.05).

Conclusions: The standard digital reusable scope performed superiorly in nearly every category, suggesting a CCD sensor may provide better image quality and performance for cases where excellent visuals are required. It is notable that the single‐use LithoVue and Axis scopes performed quite well in overall image quality. The novel evaluation instrument demonstrated internal consistency, indicating appropriateness for use in future studies.

MP06-19 Is uric acid stone the 6th component in metabolic syndrome? A marker for worsening health

H Johnson, H Musleh, A Mitry, H O'Callaghan, J Philip

Bristol Urological Institute

Introduction & Objective: A 4%‐15% lifetime risk of developing urinary stones exists. Stone disease burden is increasing, with worsening morbidity and significant economic detriment to society. Recurrence risk of 50% within ten years has been reported, suggesting an exponential financial and health burden . Uric acid stone patients are a small subgroup with significantly associated co‐morbidity. This study evaluates the natural history of uric acid stone patients.

Methods: Over five years ending 2012, medical records of all patients with a uric acid stone composition were reviewed. Medical records (primary and secondary) were reviewed for co‐morbidity, baseline blood results, subsequent interventions, and follow‐up health trajectory.

Results: 203 of 2388 stone patients (8.5%) had Uric acid stones. Mean age was 61.4 years at diagnosis (range‐17‐91 years); with average follow‐up of 40 months. Male to female ratio was 2.4:1. Half of the stones were pure uric acid. Only 63 patients had hyperuricemia on diagnosis: with 17 patients reporting a gout diagnosis. Almost all patients had significant health compromise on stone diagnosis. 112 patients had metabolic syndrome parameters, with five having cancer. Over the follow‐up period, ten patients developed metabolic syndrome with one more cancer diagnosis.

Conclusions: Uric acid stones occur in <10% stone formers. These patients have significant health compromise on diagnosis with almost all patients having metabolic syndrome. These patients should have metabolic evaluation, dietary modifications, and pharmacotherapy to reduce risk factors for metabolic syndrome. Uric acid stone diagnosis implies worsening health risk and should trigger a more aggressive multi‐disciplinary management.

MP06-20 Cost‐Effectiveness of 90‐Day Single‐Use Flexible Cystoscope Trial: Single Center Micro‐Costing Analysis

M Assmus, AE Krambeck, M Lee, DK Agarwal, M Mellon, ME Rivera, T Large

Northwestern University, Department of Urology

Introduction & Objective: Use of flexible cystoscopy for hospital based urologic care (Emergency Department, intraoperative, inpatients) is invaluable for evaluation and management of many urologic diseases. Reusable flexible cystoscopes have widespread utilization with known associated upfront purchasing, processing and service costs. Advances in single‐use flexible cystoscope development have introduced alternative options to reusable flexible cystoscopes. However, there is a paucity of cost‐effectiveness studies examining implementation of a hospital based transition to single‐use scopes. Our primary objective was a 90‐Day cost‐effectiveness evaluation of utilizing single‐use flexible cystoscopes at a tertiary care center in the United States.

Methods: Following institutional device‐approval we initiated a 90‐Day trial period (November 1, 2020 ‐ January 29, 2021) where urologic care was provided with a single‐use disposable AMBU^® aScope^TM 4 Cysto with reusable flexible cystoscopy only in cases where the single‐use scope failed or was unavailable. We performed a micro‐costing analysis examining per case cost (USD) of reusable flexible cystoscopy (including all servicing and processing costs) to the cost of the single‐use.

Results: Over the 90 day period, we encountered 85 cases (78 operative, 6 inpatient, 1 ED) where flexible cystoscopy was required. 78/85 (92%) cases were successfully completed with one single‐use disposable flexible cystoscope. Of the 7 failures, 4 were intraoperative cases where the AMBU scope failed to complete the required surgery and a reusable flexible cystoscope was required and 3 where access to the AMBU scope/monitor itself resulted in transition to reusable cystoscope use. Per use cost of the reusable flexible cystoscope at our center was $272.41 while per use cost for the single‐use is $185.00. Accounting for backup reusable scopes for disposable failures at a rate of 3 uses/month, extrapolating our data over an average 3 month period results in $9,785.71 cost savings or $39,142.84 annually.

Conclusions: This single center 90‐Day trial of single‐use flexible cystoscopies identified that based on our micro‐costing analysis, per‐use costs favor transitioning to single‐use flexible cystoscopes.

MP06-21 Predictors of flexible ureteroscope instrument repair: analysis of the last 2 years at the University Hospital Zurich

D Lavrek, C Poyet, D Schmid, T Hermanns, T Sulser, D Eberli, E Keller

Department of Urology, University Hospital of Zurich, University of Zurich, Zurich, Switzerland

Introduction & Objective: Flexible ureteroscopes are prone to damages. This study aims at evaluating procedural lifespan and hazards causing instrument repair.

Methods: All patients undergoing ureteroscopy (URS) between January 2018 and December 2019 were retrospectively identified. Medical charts were reviewed for data extraction. Only patients undergoing flexible URS were considered for analysis. Primary outcome was need for instrument repair after surgery.

Results: At total of 586 patients were identified. Of these, 486 patients (83 %) underwent flexible URS and were considered for analysis. Combination with percutaneous nephrolithotomy was found in 13 patients (3 %). Indication for surgery was stone disease in 397 (82 %), tumor in 57 (12 %), or other in 32 (7 %). Median age was 53 years (range 20 – 93). Male/female ratio was 2.03. Left/right side ratio was 1.25, with 30 bilateral cases (6%). Resident/senior operator ratio was 1.09. Lower pole URS was reported in 205 (42 %). Median operative time was 75 minutes (range 7 – 258). Ancillary device use was as follows: ureteral access sheath in 285 (59 %); laser fiber in 258 (53 %); basket in 352 (72 %). A total of 44 flexible URS needed to be sent for repair after surgery, resulting in a mean 11 interventions per instrument. Median instrument service time was 5 months (range 0.5 – 15). Univariable analysis revealed significant predictors for instrument repair: operative time (OR 1.31 for every additional 30 minutes; 95% CI 1.08 – 1.59; p = 0.007), lower pole URS (OR 2.12; 95% CI 1.13 – 4.00; p = 0.038) and laser fiber use (OR 2.01; 95% CI 1.04 – 3.90; p = 0.04). On multivariable analysis, only operative time was an independent significant predictor for instrument repair.

Conclusions: In an academic setting, each single flexible URS performs a mean 11 interventions until need for instrument repair. Operative time, lower pole URS and laser fiber use seem to be predictors of instrument repair.

MP06-22 “Are we there yet?”: Assessing the Accuracy of Artificial Intelligence in Calculating Renal Stone Volume

A Peta, C Chantaduly, P Jiang, A Brevik, L Limfueco, R Karani, R Arada, RM Patel, J Landman, P Chang, RV Clayman

Department of Urology, University of California, Irvine

Introduction & Objective: True stone burden in urolithiasis patients is vastly underestimated due to the use of only one or two dimensional measurements on plain x‐ray images or on computed tomography (CT) scans. With modern software, manual segmentation of a stone in CT images is able to create a true three‐dimensional (3D) volume. We sought to employ a deep learning technique, using convolutional neural networks (CNN), to automate the segmentation and volume calculation of renal stones on CT imaging.

Methods: A total of 771 renal stones from 119 unique patients were included in the study. For each stone, volume was calculated based on manual 3D volumetric segmentations of CT imaging, considered the ground truth. Volumes of each stone were also calculated with the European Association of Urology (EAU) ellipsoid formula. Using an initial seed point manually identified for each stone, a CNN algorithm was trained for stone detection and segmentation. Specifically, a 20 layer fully‐convolutional contracting‐expanding CNN spanning 473,410 parameters was designed to detect and segment renal calculi within a 48 x 48 x 48 voxel cube in the vicinity of the seed point. Both a Pearson correlation coefficient and Dice score, a metric of spatial overlap, were used to assess model performance against manual segmentations. Total statistics were aggregated after five‐fold cross‐validation.

Results: The CNN algorithm calculated stone volumes compared to manually segmented stone volumes had a dice score of 0.56 and a Pearson correlation coefficient (r value) of 0.82. Volume calculations with the EAU ellipsoid formula had a weaker correlation with the manually segmented volumes (r = 0.75).

Conclusions: Deep learning convolutional neural networks can automatically segment renal stones and estimate stone volume better than traditional validated volume formulas. Further refinement of the CNN is needed for auto‐segmented stone volumes to reach the same accuracy as manual segmentations.

MP07-01 Comparing PSMA‐PET, biopsy pathology, and MRI for prediction of Extra‐prostatic extension (EPE) and surgical guidance in prostate cancer

CD Bahler, M Green, M Tann, K Collins, J Swensson, E Brocken, L Cheng, D Alexoff, H Kung, M Koch

Urology

Introduction & Objective: Injury to nerves and muscle tissue during prostatectomy causes incontinence and impotency. However, preserving nerves and muscle adjacent to prostate cancer risks positive margins; therefore, prostatectomy would benefit from guidance of more accurate imaging.

Methods: A retrospective analysis was performed of clinical trials for PSMA‐PET targeted imaging (⁶⁸Ga‐P16‐093 or ⁶⁸Ga‐PSMA‐11) prior to prostatectomy. ⁶⁸Ga‐P16‐093 has up to 3‐times less excretion in urine as compared to PSMA‐11. A blinded review of PET and MRI scans was performed to predict the risk of extra‐prostatic (EPE) extension at the right or left nerve bundle. Stata 13.1, Pearson's Chi², and McNemar's Chi² were used for accuracy statistics.

Results: A total of 46 patients were imaged with either ⁶⁸Ga‐P16‐093 (n = 25) or ⁶⁸Ga‐PSMA‐11 (n = 21) PET imaging. Age (62 vs 63 years), PSA (7.3 vs 7.9), and biopsy pathology (3 + 3: 0 vs 5%, 3 + 4: 28 vs 29%, 4 + 3: 24 vs 19%, ≥4 + 5: 48 vs 48%) were similar between the groups (p > 0.30). There were 17 (37%) with pT3a (EPE) and 12 (26%) with pT3b on final pathology. Overall positive margin rate was 12 (26%). Index lesion SUV_max was similar between P16‐093 and PSMA‐11 (10.3 vs 10.0). EPE Sensitivity (87 vs 94%), Specificity (77 vs 76%), and ROC area (82 vs 85%) were similar between P16‐093 and PSMA‐11, respectively (p = 0.32). MRI (available in 23) found high specificity (89%) but low sensitivity (63%) and the overall ROC area was lower when compared to pooled PSMA‐PET (.76 vs .84, p = 0.04). For pooled PSMA‐PET imaging, a treatment change from “non‐nerve sparing” to “nerve sparing” was recommended in 17/46 (37%) of patients. A total of 10 men had nerve‐sparing (treatment change) based on PSMA‐PET imaging with one (10%) having a positive margin. Figure 1 shows a case where the cancer was away from the nerve‐bundle on PSMA‐PET imaging.

Conclusions: PSMA‐PET imaging can improve surgical guidance resulting in preservation of nerve‐bundles. ⁶⁸Ga‐P16‐093 PET and ⁶⁸Ga‐PSMA‐11 PET had similar accuracy for predicting extra‐prostatic extension.

MP07-02 Targeted MRI/US Fusion and Standard TRUS Prostate Biopsy: 563 Patients ‐ Relationship Between PIRADS Score and Prostate Cancer Detection Rate: A Single Urologist's Experience

A Kasraeian, M Alcantara, K Mola Alcantara, J Yellin, A Brochert, J Cesaretti, A Kasraeian

Kasraeian Urology

Introduction & Objective: Multi‐parametric MRI (mpMRI) and targeted MRI/Ultrasound fusion prostate biopsy (tMRI/US FPB) are important tools in the diagnosis of prostate cancer (PCa). We report our experience with a total of 563 patients. Specifically, we report the relationship between PIRADS score and overall positive biopsy rate as well as detection rate of Gleason (G) 7 or higher PCa in men.

Methods: Data was prospectively collected and analyzed on 563 men undergoing tMRI/US FPB and TRUS standard biopsy between January 2017 and December 2020. In all patients, mpMRI was interpreted by a single radiologist using the PIRADS scoring system. 3D rendering of regions of interest was performed prior to tMRI/US FPB performed by a single urologist using the Invivo UroNav System. Concurrent standard 14 core biopsy (14Bx) was performed in all cases. Data was Prospectively collected and analyzed.

Results: Prostate biopsy was performed on 563 men between January 2017 and December 2020 of whom 62% (350/563) were diagnosed with PCa. Of men diagnosed, 63% (220/350) were diagnosed with G7 or higher disease. Among PIRADS 3 Fusion biopsies, the positive rate for PCa was 68% (127/178) with 46% (82/178) being G7 or higher disease (15% (26/178) G8‐9 PCa). Additionally, among PIRADS 4 Fusion biopsies, the positive rate for PCa was 95% (38/40) with 93% (37/40) being Gleason 7 or higher disease (38% (15/40) G8‐9 PCa). Lastly, among PIRADS 5 Fusions prostate biopsies 93% (14/15) were positive for a PCa with all but one being a G7 PCa or higher 87% (13/15) and 67% (10/15) being G8‐9 PCa. The overall positive rate for MRI‐US Fusion prostate biopsies was found to be 74% (198/268). G7 or higher disease was found in 53% of those men (with 20% being G8‐9 PCa). The TRUS standard prostate biopsy positive rate was 51% (151/295) with 18% being G7 or higher disease (3.7%, G8‐9 PCa).

Conclusions: tMRI/US FPB is an important technology which increases the diagnostic yield of prostate biopsy when combined with 14Bx. In our series, the increased positive biopsy rate with combined tMRI/US FPB‐14Bx was statistically significant when compared to 14Bx alone. In addition, tMRI/US FPB‐14Bx found more Gleason 7 or higher PCa. Lastly, PIRADS 4 and 5 lesions on mpMRI were associated with higher rate of both overall and Gleason >7 PCA detection.

MP07-03 Retrograde uretero‐pyelography without diagnostic ureteroscopy has superior intravesical recurrence‐free survival compared to performing ureteroscopy in nephroureterectomy for upper urinary tract urothelial carcinomas

K Kim, H Yang, S Kim, D Kim, C Lee, Y Jeon

Department of Urology, Soonchunhyang University Cheonan Hospital, Soonchunhyang University College of Medicine

Introduction & Objective: Ureteroscopy prior to nephroureterectomy (NU) is a practical and powerful tool to diagnose upper urinary tract urothelial carcinomas (UTUC). However, ureteroscopy before NU has a potential limitation which could pose a risk factor for intra‐vesical recurrence. Therefore, we tried to identify the risk factor of intravesical recurrence after NU, and to investigate whether retrograde uretero‐pyelography (RGP) without diagnostic ureteroscopy could be another diagnostic option in UTUC.

Methods: From total 77 UTUC patients who underwent NU, 65 patients were finally enrolled in this study, 12 patients who underwent NU without further evaluation after a computed tomography examination were excluded. Univariate and multivariate analyses based on Cox's regression were performed to identify independent prognostic factors for intravesical recurrence‐free survival (IVRFS) after NU.

Results: From the total 65 patients, 32 patients have underwent diagnostic ureteroscopy and 33 patients have underwent RGP without ureteroscopy before nephroureterectomy. Patients who received RGP without diagnostic ureteroscopy were found to have significantly superior IVRFS compared to patients who received diagnostic ureteroscopy by Kaplan‐Meier curve analysis (p = 0.022). RGP without ureteroscopy before nephroureterecomy (hazard ratio, 0.388; p = 0.030) was a significant independent predictor of IVRFS after radical nephroureterectomy.

Conclusions: The diagnostic ureteroscopy procedure prior to nephrouretrectomy has a significant effect on IVRFS. RGP without diagnostic ureteroscopy can be another diagnostic option to reduce intravesical recurrence after NU in UTUC.

MP07-04 Defining the non‐contrast computerized window setting for optimal colon identification prior to percutaneous nephrolithotomy

S Dekalo, Z Savin, I Mintz, H Hertzberg, I Masarwe, G Aviram, O Yossepowitch, M Sofer

Tel‐Aviv Sourasky Medical center, Sackler School of Medicine, Tel‐Aviv University

Introduction & Objective: Colonic injury during percutaneous nephrolithotomy (PCNL) is a rare, however, disastrous complication. Therefore, preoperative accurate identification of colon on cross sectional imaging, usually non‐contrast computed tomography (NCCT), is essential in planning the access and reducing the risk of its occurrence. The lack of contrast material, collapsed bowel segments and previous intraabdominal operations may limit proper colonic recognition on NCCT. We aimed this study to assess which NCCT window setting provides the optimal colonic identification for PCNL preoperative planning.

Methods: Twenty‐two axial NCCT images of 11 consecutive patients scheduled for PCNL were reviewed by a senior endourologist who chose the most representative ones for planning the PCNL puncture. Ten urologic surgeons (4 specialists, 6 residents) reviewed these images in a randomized blinded order using 2 window settings (abdomen and lung). They were asked to mark the colonic area in each image using a dedicated commercially available area calculator software (Bluebeam, Pasadena, USA). Statistical assessment was conducted.

Results: Overall, the mean marked colonic area was greater in the lung window in comparison to abdomen window: 8.82 cm² vs 7.4 cm², respectively, p < 0.001). Changing the CT‐window from abdomen to lung resulted in increased identified colonic area in 44 images (50%), similar area in 30 images (34%) and decreased area in 14 images (16%). Intraclass correlation showed good agreement between the senior readers and among all readers (0.92 and 0.87 respectively). Senior urologists had consistent area measurements (no difference in area measurements between abdomen and lung windows) in 13/22 cases, while residents had no difference in area measurements in only 17/66 cases (p = 0.008).

Conclusions: Lung window solely or in combination with abdomen window appear to provide the most accurate colonic demarcation for pre‐operative planning of PCNL access. This pattern is more evident among young urologists and may reduce the risk of colonic injury.

MP07-05 ABSTRACT WITHDRAWN

MP07-06 MRI/TRUS target prostate fusion biopsy learning curve in two residents at a referral center: a retrospective analysis on more than 1000 procedures

E Checcucci, F Piramide, D Amparore, S De Cillis, G Volpi, A Piana, S Granato, A Pecoraro, P Alessio, B Carbonaro, J Mézière, G Cattaneo, F Ragni, M Manfredi, C Fiori, F Porpiglia

Department of Urology, AOU San Luigi Gonzaga ‐ University of Turin

Introduction & Objective: During last years, prostate cancer (PCa) detection has been improved by the implementation of software allowing to perform MRI‐transrectal ultrasonography fusion‐guided prostate biopsy (MRI/TRUS fusion biopsy, FB). The aim of our study was to assess the learning curve (LC) of two urology residents in the execution of fusion biopsy (FB) considering overall prostate cancer (PCa) and clinically significant (cs) PCa detection rate (DR), based on different lesions' characteristics at the MRI.

Methods: We extracted data from our prospectively maintained database from January 2015 to December 2019. FB was carried out with the BioJet fusion system (D&K Technologies, Barum, Germany) either by a transrectal or transperineal approach. An ANOVA test was used to assess the homogeneity of the cohort. Multivariable linear and logistic regression analysis were used to assess the correlation between operator experience and DR for PCa and csPCa. At last, the postprocedural complication rate trend was determined.

Results: 1005 men were enrolled in the study. During the five years of the study, the pre‐biopsy characteristics of the patients enrolled did not change significantly except for the proportion of patients who previously underwent prostate biopsy (p < 0.001) and the number of mpMRI performed at referral centers (p = 0.002), both showing a decreasing trend over time. The overall DR of PCa was 61.2% (615/1005) [IC 0.58 ‐ 0.64]; whilst DR for csPCA was 54.6% (549/1005) [IC 0.51 – 0.57]. Operator experience does not appear to impact the DR of overall PCa and csPCa. On the contrary, in case of lesions with diameter <8 mm, PCa and csPCa DR were significantly higher with operator experience (p = 0.048 and p = 0.038, respectively). Considering the suspicious tumours located in the more challenging areas of the prostate (transitional or posterolateral zone) were not significantly better diagnosed with experience improvement (p = 0.34 and p = 0.22 for PCa DR and csPCa DR respectively). The specific analysis focused on PI‐RADS 5 lesions, mpMRI performed in referral centers, or for patients at repeated‐biopsy did not reveal a significant relationship between operator experience and PCa or csPCa DR. Complication rate was stable during the whole study (p = 0.75).

Conclusions: A standardized FB approach demonstrated to be feasible, safe, and effective since the start of residents' LC. PCa and csPCa DR was stable, after >1000 biopsies. Nevertheless, in case of lesions <8 mm, the execution of at least 100 FB is fundamental in order to correctly sample the area.

MP07-07 New indication algorythms for Active Surveillance in the era of MRI‐targeted prostate biopsies

C Wetterauer, J Federer‐Gsponer, F Leboutte, R Mona, J Ebbing, C Rentsch, L Manka, H Seifert, S Wyler, F Recker, M Kwiatkowski

University Hospital Basel, Department of Urology

Introduction & Objective: Active surveillance (AS) strategies have been established to avoid overtreatment of low risk prostate cancer (PCa) patients. Low tumor volume, as reflected by the number and the percentage of positive biopsy cores, represents one of the indication criteria for AS. Applying this criterion after MRI targeted prostate biopsies might lead to an overestimation of the tumor volume, wherefore patients who would actually be suitable for an AS strategy would be exposed to the risk of being over‐treated.

Methods: This retrospective analysis included 318 patients in which PCa was detected by MRI‐TRUS‐fusion prostate biopsy. Biopsies were performed at two Urological centers in Switzerland between January 2016 and November 2018. We assessed the effect of targeted biopsies and temporary rating strategies on eligibility for AS, and developed new algorithms. Patients were grouped according to “classic” Epstein criteria and an “extended” definition including Gleason 7a. We developed a “composite 1” definition based on the prostate specific antigen (PSA) and the Gleason Score in all biopsies in combination with the number of positive random biopsies and according tumor involvement; and a “composite 2” definition based on PSA, the Gleason Score in all biopsies in combination with MRI measured tumor volume.

Results: Based on random biopsies only, 44 of the 318 patients (13.8%) qualified for AS according to current guidelines, and 60 patients (18.9%) fulfilled the extended indication criteria for AS including Gleason 7 disease. Targeted biopsies identified ineligibility for AS according to the classic indication in 24 of the 44 patients (54.5%), and according to the extended indication in 36 of the 60 patients (60.0%). The reasons for ineligibility for AS according to classic and extended indication were upstaging of Gleason score in 9 and 5 patients, identification of more than 2 positive biopsies in 11 and 19 patients, and identification of more than 50% tumor load in 5 and 8 patients, respectively. Application of the “composite 1” definition led to the AS eligibility of 52 of 248 patients (20.97%) in the “classic” and of 77 of 248 patients (31.05%) in the “extended” group. Classic rating strategies as well as the “composite 1” score included a significant rate of patients with tumor volume of more than 0.5cm³.

Conclusions: Classic rating strategies tend to underestimate tumor volume whereas targeted biopsies lead to overstimation of tumor volume. We could demonstrate that classic algorithms led to formal ineligibility of patients for AS and propose a new imaging based rating algorithm to improve tumor assessment for a more accurate indication for AS.

MP07-08 Intraoperative Contrast Enhanced Ultrasound To Reduce Unnecessary Ureteral Stent Placement After Ureteroscopy

J Ahn, D Bayne, F Hamouche, M Stoller, T Chi

UCSF

Introduction & Objective: Ureteral stents are a significant source of morbidity. The decision to place one at the time of retrograde intrarenal surgery (RIRS) is often subjective and based on limited clinician judgement. A reliable tool is needed to guide urologists and avoid unnecessary stent placement. Contrast enhanced ultrasound (CEUS) is a safe, readily adaptable technology where a microbubble contrast agent is instilled into the upper urinary tract (Figure 1). We propose an intraoperative retrograde CEUS test during RIRS to help predict post‐operative ureteral drainage and the need for ureteral stent placement.

Methods: For this pilot feasibility study, we performed CEUS in patients undergoing RIRS for nephrolithiasis. After stone treatment, the renal collecting system was decompressed, then 1 ml of CEUS contrast and a 2 ml flush was instilled per ureteral catheter. For the flush, iodinated contrast was substituted for saline to permit comparison of CEUS with fluoroscopic drainage. After catheter removal and 2 minutes for ureteral rest, the bladder was cycled with irrigation and then scanned with CEUS and fluoroscopy for passage of either contrast agent (Figure 1). Ureteral stent placement was determined based on preexisting standard of care. Post‐operative unplanned encounters (PUE) including patient calls, emergency visits, and hospital admissions were tracked.

Results: 41 renal units from 39 patients underwent CEUS during RIRS (Figure 2). Stent omission was successful with no PUE in 91% (21/23 units) with CEUS drainage. Compared to those who had a stent placed based on no CEUS drainage, those who did not have a stent based on drainage had a significantly lower incidence of complications (9% vs 53%, p = 0.006) Fluoroscopic drainage was discordant with CEUS drainage in 12 renal units. In all cases of discordance, drainage was seen on CEUS but not on fluoroscopy.

Conclusions: CEUS is a novel means to objectively assess upper tract drainage at the time of RIRS. Our results suggest that retrograde CEUS could predict successful stent omission and may be more sensitive for predicting drainage than fluoroscopy due to low contrast volumes.

MP07-09 Using Hounsfield unit (HU) ‐ volume models of kidney stones to predict successful stone dusting during retrograde intra‐renal surgery (RIRS)

D Kim, S Jeon, S Lee, C Lee, S Chang, S Lee

Department of Urology, School of Medicine, Kyung Hee University

Introduction & Objective: Computer tomography (CT) of renal stones and measurement of their Hounsfield unit (HU) is commonly used for evaluation before the treatment of urolithiasis. We measured the volume of all HUs in a single stone and drew a model depicting the stone's HU distribution in order to predict success of dusting technique during retrograde intrarenal surgery (RIRS).

Methods: The medical records of 131 patients who underwent RIRS from January 2018 to January 2019 at Kyung Hee University Hospital were reviewed and 168 kidney stones were initially examined. Stones that were larger than 1cm were included and a total of 49 patients with 55 stones were evaluated. The stones were divided into two groups according to intra‐operative dusting success. Dusting was considered successful when stone disintegration was achieved with a laser setting of energy 0.2‐0.4 J and frequency 50 Hz. If higher laser energy settings (fragmentation) and extraction was needed, it was considered as dusting failure. 3‐dimensional models of the stones were reconstructed, and maximal HU, minimal HU, difference between max and minimal HU, HU standard deviation, stone volume, volume of peak HU was evaluated.

Results: Among the total 55 stones, 32 were successfully dusted and 23 were fragmented during surgery. Dusted stones showed a more heterogenous distribution of HU while fragmented stone HUs were more homogenous. “Success of dusting” group had higher mean difference in max and minimal HU (1102.94 ± 376.63 vs 794.91 ± 415.05, p = 0.0073), higher HU standard deviation (262.73 ± 112.61 vs 155.65 ± 95.69, p = 0.001)) and smaller volume of peak HU (4.52 ± 2.53 vs 13.28 ± 8.10, p < 0.0001). When we drew histograms of the HU, dusted stones were wide and rugged while fragmented stones were mostly narrow and peaked.

Conclusions: Stone reconstruction models and evaluation of HU volumes showed that stones with smaller peak HU volumes and higher differences in max and minimal HU could be considered more fragile and prone to successful dusting. Stones that show this type of HU distribution should be considered candidates for RIRS even if their size is larger than current recommendations.

MP07-10 Human vs Machine: Comparison Of Manual CT Measurements Versus Automated Software Of Stone Phantoms

L Peard, M Cash, I Mohamed, AM Harris, JR Bylund, AA Bhalodi, J Lee, J Bell

Univeristy of Kentucky

Introduction & Objective: Given the significance of stone size in management of urolithiasis, obtaining accurate and precise measurements is paramount. We compared software and manual stone length and volume measurements to actual measurements of stone phantoms.

Methods: Seventeen unique stone phantoms were created in a variety of shapes and sizes using BegoStone Plus. Stone length, width, and height were measured with electronic calipers. Stone volume was measured using volume of displacement in water. Stone phantoms were placed in saline and imaged with CT. CT images were uploaded into post‐processing software which analyzed the stones for maximum length and volume. Two urologists assessed the imaged stones for length, width and height and were blinded to the software measurements. Stone volume was calculated using the ellipsoid formula 0.52 x length x width x height.

Results: The stone phantom length ranged from 5.5mm to 63mm with volumes of 40mm³ to 16,000mm³ (Figure 1). The software had the closest approximation to the actual stone length with a median percent error of 6.2% (IQR 3.1%‐9.4%). Readers 1 and 2 had median percent errors of 5.7% (IQR 3.7%‐14.1%) and 7.8% (IQR 2.1%‐17.2%) respectively. Reader 1 and 2 both differed from the software with median percent differences of 16% (IQR 8.6%‐22.4%) and 17.1% (IQR 5.2%‐28.4%). The readers had a median percent difference from each other of 4.1% (IQR 3%‐6.6%). None of the length measurements by the software or the human readers differed significantly from the actual stone phantoms (P > 0.610). The percent errors with regards to volume for the software, reader 1 and reader 2 compared to actual stone volume were 20% (IQR 14.2%‐30%), 18% (IQR 5.2%‐39.8%), 24.1% (IQR 10.2%‐33.2%), respectively. Reader 1 and 2 differed from the software with median percent differences of 33.1% (IQR 21.7%‐59.5%) and 26.3% (IQR 15%‐48%), respectively. The readers had a median percent difference from each other of 17.3% (IQR 7.5%‐32.5%). None of the measurements by the software or the human readers differed significantly from the actual stone phantom volume (P > 0.697).

Conclusions: Software measurements approximated the actual measurements for the stone phantoms while eliminating interobserver variability. Using post‐processing software to measure urinary stones appears to be as accurate as human readers, but with greater precision.

MP07-11 Xray and US free calix puncture before PCNL (XUF PCNL). Comparison with standard Xray/US guided puncture

M Maltagliati, L Berti, C Buizza, U Besana, A Calori, M Justich, C Gastaldi, M Sighinolfi, S Micali, BC Rocco, G Bozzini

ASST Valle Olona

Introduction & Objective: The most challenging part of a percutaneous nephrolithotomy (PCNL) is the perfect puncture of the planned calyx. HoloLens based augmented reality system has been descibed as an helpful tool to assist the surgeons in different fields. After the evaluation of this new technique with an ex vivo model we planned a clinical study to compare the standard puncturing technique fluoroscopy and ultrasound guided with the this new Augmented Reality Technique.

Methods: We performed a matched pair analyses and created two groups with 20 patients each. In one group a standard ultrasound and fluoroscopy guided puncture was perfomed and in the other group the XUF PCNL assisted puncture of the renal pelvis was performed. To puncture the collecting system with the HoloLens augmented reality, we placed three radiopaqued markers from the radiotherapy on the patients skin around the kidney. A preoperative multi‐slice CT with a low dose and a late‐contrast phase was taken in prone position on a specific PCNL‐cushion as it is used during surgery. The markers, as well as all needed organs such as kideny, stone, bowel, liver etc. were segmented with a proper software to mimic also their movement during puncture. For the surgery the patient is placed in the same position as for the CT and the radiopaqued marker are replaced with coloured markers in two rows. The HoloLens are used as a glass‐camera to guide surgeon's hands and needle. The puncture is then perfomed. We measured the radiaion exposure, puncture time and attempts to a successful puncture in the two Groups. The complications were also documented.

Results: There was a significant difference between the radiation exposure and the puncturing time regarding the two techniques. There was no significant difference regarding the puncture attempts between the two puncturing techniques (p‐value = 0.45).

Conclusions: The XUF guided puncture can be compared to the standard puncturing techniques and is a feasible method for planning a puncture for patients with complicated nephrolithiasis. The great advantage is the Xray free exposure An HoloLens device is mandatory to complete a XUF PCNL.

MP07-12 Should the Pelvis be Included in CT Imaging of Asymptomatic Urinary Stone Patients? A Retrospective Review

M Fritz, J Zhang, A Ayoob, J Bell

Univeristy of Kentucky

Introduction & Objective: CT is often used for surveillance of urinary stone disease because of its superior stone imaging characteristics, however, it confers more radiation than renal US or x‐ray. In an effort to decrease radiation, we evaluated the effects of eliminating the pelvis from the CT scan for asymptomatic follow‐up patients with urolithiasis.

Methods: We queried our medical record for any CT Abdomen/Pelvis (Abd/Pelvis) between January 2017 to April 2019. We then narrowed the cohort by looking at patients who had this done in preparation for a routine stone visit with one of our endourology providers. Patients were excluded from analysis if the record was incomplete or if it indicated they were symptomatic from stones at the time of the visit. The abdominal region was defined as T11‐L5 (Figure 1). CT scan images were reviewed to see if any stones or significant pathology would have been missed by only having the abdominal images. Effective radiation doses (ED) were estimated from CT imaging using VirtualDoseTMCT software (Virtual Phantoms, Inc). Institutional charges for Medicare were queried and compared for: CT Abdomen/Pelvis, CT Abdomen, Renal US, and KUB.

Results: 80 patients were included in our analysis with 61 patients having non‐obstructing stones on these scans. The mean age was 53 (range = 20‐81) with a mean BMI was 32 (± 8.7). None of the patients were found to have any new, clinically significant stone‐related pathology in the pelvis. 13 patients had incidental pelvic findings that required no intervention (ex, prostatomegaly or thickened bladder). The mean effective dose reduction of eliminating the pelvis was 45% (7.9 mSv vs 4.4 mSv). The mean Medicare charges for imaging studies were as follows: CT Abd/Pelvis = $4,179, CT Abd = $2,458, Renal US = $1,190, and KUB = $471.

Conclusions: Excluding the pelvis does not appear to miss any ureteral stones in asymptomatic patients presenting for routine follow‐up. This appears to be an effective and easy way to reduce both cost and radiation while not missing any significant pathology.

MP07-13 Does CT scan after ultrasonography change surgical planning for nephrolithiasis?

A Ludvigson, P Motamedinia

Yale New Haven Hospital

Introduction & Objective: Ultrasound (US) is often used to diagnose nephrolithiasis, but it is less accurate than CT scan, potentially affecting surgical plans. We examined how often obtaining a CT scan after US changed the indicated management of nephrolithiasis, to see if risk factors that determine inaccurate US scans could be identified.

Methods: Approval was obtained through our institutional IRB. From those who presented to our health system over the past 3 years with suspected nephrolithiasis, we selected patients who had undergone a retroperitoneal US, and then a CT scan within 30 days. We recorded stone size and location for all studies. We recorded stone density and skin‐to‐stone distance for each CT scan. Using current AUA guidelines, we determined the indicated procedure based on findings of each imaging study: shockwave lithotripsy (SWL), ureteroscopy (URS), or percutaneous nephrolithotomy (PCNL). We used Minitab software to perform all statistical analysis, i.e. general linear models and two‐tailed Student's t‐tests.

Results: 305 patients met inclusion criteria. Of these, the CT scan changed the indicated procedure 108 times (35.4%). 26 US studies indicated SWL; CT changed 19 of these (73%). 129 US studies indicated URS; CT changed 62 of these (48%). 24 US studies suggested PCNL; CT changed 9 of these (37.5%). Using CT as the gold standard, 18 US studies were false positive for stones (sensitivity = 0.72). 51 US studies were false negative for stones (specificity = 0.86). Average body mass index (BMI) was significantly lower in the patients with a false positive US as compared to those with a true positive US (26.59 versus 29.13 kg/m2, t(24) = 2.33, p = 0.029). When comparing patients who had their indicated procedure changed by the CT scan to those who did not, there were no significant differences in age, BMI, or skin‐to‐stone distance. However, those who had their procedure changed had significantly lower density stones (566.1 versus 747.5 HU, t(154) = 2.92, p = 0.004). When patients were examined in subgroups based on what their indicated procedure was before and after the CT scan, there were also no significant differences based on age, BMI, or skin‐to‐stone distance. There was a significant difference based on HU, with stone density explaining 22.88% of the variation (F(11,154) = 4.15, p < 0.001).

Conclusions: US has many advantages over CT, but cannot always be used in place of it. Our study demonstrates that a CT scan changes the indicated stone treatment in more than 1/3 of cases, and that lower‐density stones are a risk factor for inaccurate US findings. US should be used with particular caution in those with a history of low‐density stone types, and for SWL surgical planning.

MP07-14 Utilization of low‐dose CT for evaluation of urolithiasis at a high‐volume stone referral centre

EP Chan, F Gabrigna Berto, O Daher, Z Syed, C Dawson, J Amann, J Bjazevic, H Razvi

Western University

Introduction & Objective: Non‐contrast computed tomography of the kidneys, ureters, and bladder (CT KUB) is the gold standard for evaluation of urolithiasis. Radiation from repeat CT increases the risk of secondary malignancy and physicians should strive for radiation doses as low as reasonably achievable. Low‐dose CT (LDCT; < 4mSv) has excellent performance in the diagnosis of urolithiasis. The objective of this study is to evaluate the utilization of LDCT at a high‐volume endourology centre.

Methods: A retrospective study was performed for CT KUB performed at St. Joseph's Hospital (London, Canada) in the month of January in 2011, 2013, 2015, 2017, and 2019 for stone assessment. Mean radiation dosage, tube voltage, encounter type, requisition details, umbilical fat thickness (UFT) was obtained from imaging software. UFT <2.5cm was used as a surrogate for BMI <30m/kg². Patient age, sex, and need for further imaging for diagnosis following initial CT KUB was documented from the electronic record.

Results: A mean of 50 scans were performed each January (N = 250). Studies were performed with 120 kV on the GE 64 Slice Discovery HD 750. Mean radiation dosage was 5.7 mSv (2.9‐20.4 mSv). Overall LDCT utilization was 50.8% and was 35.7%, 54.5%, 53.2%, 49.1%. and 58.1% in 2011, 2013, 2015, 2017, and 2019, respectively. Of CT KUB ordered by urologists for stone evaluation, only 50.5% were LDCT (mean: 5.6 mSv). Factors associated with LDCT included female gender (59.3% vs 43.8%; p = 0.016) and low UFT (64.2% vs. 42.9%, p < 0.001) No patients required further imaging tests to clarify the diagnosis of urolithiasis following the initial CT scan.

Conclusions: Reducing radiation exposure is important for patients being evaluated for urolithiasis. Despite widespread knowledge regarding LDCT protocols and urologist expectations that LDCT should be employed, this only occurs about half the time at a high‐volume centre, even when the requisition is specific for evaluation of stones and BMI <30 kg/m². Regular evaluation of LDCT utilization and collaboration between urology and medical imaging departments is critical for improvement of radiation safety outcomes.

MP07-15 A Comparison of Radiation Exposure Between the New Flat Panel and the Conventional Round C‐Arm

JD Belle, M Keheila, N Chen, J Lee, N Srikureja, AS Amasyali, DD Baldwin, M Hajiha

Loma Linda University, Department of Urology

Introduction & Objective: Radiation exposure is a significant concern for patients and health care providers. Manufacturers of flat panel C‐arms have claimed reduced radiation exposure, however, the dose delivered at the lowest possible settings for each C‐arm type has not been compared. The purpose of this study was to compare the cumulative radiation dose between the OEC Elite CMOS Flat Detector (FD) and the conventional OEC 9800 Image Intensifier C‐Arm (Round) in a cadaver model.

Methods: Optically stimulated luminescence (OSL) chips were implanted into a cadaver as seen in Figure 1. Five trials were performed at six different C‐arm settings: round 1PPS (lowest possible setting) at standard and low dose, round 4PPS at standard and low dose, and FD 4PPS (lowest possible setting) at standard and low dose. All trials used five minutes of fluoroscopy with automatic brightness control. Radiation dose and settings were compared using t‐tests, with p < 0.05 considered significant.

Results: When comparing the FD and Round C‐arms at their lowest possible pulse settings, the FD produced 3‐5 times more radiation exposure at all locations using standard dose settings (Table 1). This difference was maintained in all locations at low dose settings (p < 0.05 for all, data not shown). When comparing FD and Round C‐arms at 4PPS, radiation exposure from the FD was about 2x higher when using standard exposure settings (Table 1). At low dose settings and 4PPS, the FD and Round C‐arms produced equivalent radiation exposure at all locations (P > 0.05 for all).

Conclusions: While modern flat panel detector C‐arm manufacturers advertise lower radiation exposure, when FD machines are utilized at the lowest pulse settings they produce approximately 4x greater radiation exposure than the Round panel at the lowest pulse settings. At both standard and low dose settings, the round C‐arm produced significantly less radiation exposure. When it is imperative to have the lowest possible radiation exposure, for example when operating on pregnant patients or in children, older round C‐arms should be utilized.

MP07-16 Clear cell Likelihood Scores (ccLS) on Multiparametric MRI Decreases Benign Pathology Rates in Patients with Chronic Kidney Disease (CKD) Being Considered for Extirpative Nephron Sparing Surgery (NSS)

TN Morgan, JC Dai, V Kommidi, S Kusin, H Kominsky, I Pedrosa, JA Cadeddu

UT Southwestern

Introduction & Objective: NSS is favored for patients with solid renal masses (SRM) and concurrent CKD. Complication rates are higher than average and operating for benign disease is less permissible. We describe complications and benign pathology rates in a cohort of CKD patients undergoing roboticassisted partial nephrectomy (RAPN) with utilization of MRI and clear cell likelihood scoring (ccLS).

Methods: A retrospective chart review was performed on 70 patients with CKD (eGFR 15‐60) and a pre‐operative MRI who underwent RAPN between 4/2016 and 2/2020. CcLS scores from 1 to 5 (1‐very unlikely, 2‐unlikely, 3‐equivocal, 4‐likely, and 5‐very likely) were assigned prospectively pre‐operatively in 54 (77.1%), and post‐operatively in the remainder by a blinded radiologist. Clinical characteristics were analyzed using SPSS. Wilcoxon signed rank test compared change in post‐operative GFR from baseline (IBM, Armonk, NY).

Results: Patient demographics and pre‐operative tumor characteristics are in Table 1. The median OR time, blood loss, warm ischemia time and length of stay were 180.5 minutes (IQR 156.0‐204.0), 200.0 cc (IQR 100.0‐300.0), 23.0 minutes (IQR 18.0‐26.0), and 2.0 days (IQR 1.0‐3.0), respectively. ccLS scores were 1‐5 in 13 (18.6%), 5 (7.1%), 17 (24.3%), 14 (20.0%), and 21 (30.0%), respectively. All patients had a negative margin, and only 4 patients (5.7%) had benign final pathology, outlined in Table 2. One or more complications occurred in 8 patients (11.4%). The median post‐operative eGFR (45.0, IQR 33.0‐56.0) obtained at a median of 24.9 months (IQR 5.5‐51.3) was not significantly lower than baseline (49.0, IQR 36.0‐53.0, p = 0.67).

Conclusions: RAPN in CKD patients requires careful consideration given increased risk of complications and progression to ESRD. MRI with ccLS scoring may decrease the rate of benign or indolent pathology and even obviate the need for renal biopsy or radical nephrectomy in select cases. Further prospective studies are required.

MP07-17 Variation in Imaging after Stone Treatment

J DiBianco, B Conrado, S Daignault‐Newton, S Jafri, H Korman, KR Ghani, CA Dauw, f Urological Surgery Improvement Collaborative

Department of Urology, University of Michigan

Introduction & Objective: Imaging after stone treatment is an important recommended step to assess stone clearance and identify potential complications. We assessed prevailing practice patterns of post‐SWL and post‐URS imaging to identify areas for quality improvement.

Methods: Reducing Operative Complications from Kidney Stones (ROCKS) is a quality improvement initiative from the Michigan Urological Surgery Improvement Collaborative (MUSIC). Trained abstractors prospectively record standardized data elements from the health record in a web‐based registry. Using the ROCKS registry, we identified patients undergoing SWL and URS between June 2016 and December 2019. The frequency and modality of postoperative imaging within 60 days was assessed. Variation in imaging was evaluated at the practice level by those with ≥10 SWL and URS cases per year, as well as the urologist level with ≥5 SWL and URS cases per year. Demographic, clinical and operative data were compared using bivariate and multivariable analyses to understand factors associated with post‐SWL and post‐URS imaging.

Results: 14,894 cases were identified (5273 SWL and 9621 URS) from 33 practices and 205 urologists. Overall, postoperative imaging was obtained in 49.1% of patients. Significant differences were seen with respect to imaging following SWL and URS (72.4% vs 36.3%, p < 0.01). The most common imaging modality for patients following SWL was KUB (63.9%), KUB plus US (17.2%), and US (11.1%) while after URS it was US (35.5%), KUB (34.7%), CT (13.7%), and KUB plus US (9.6%). Substantial practice and provider‐level variation was seen in postoperative imaging following SWL (range 36‐95.2%) and URS (range 0 – 93.1%) (Figure). The odds of imaging post‐URS compared to post‐SWL were significantly different by practice (p < 0.001) after factor adjustment (odds by practice: range 0.02 – 1.96). Additional factors associated with 60‐day postoperative imaging included higher Charlson comorbidity index (CCI), larger stone size and renal stone location.

Conclusions: The postoperative imaging rate for SWL is almost double the rate for URS in the state of Michigan. Wide variation exists amongst practices and providers with respect to imaging, with no apparent correlation amongst those practices imaging at a high rate for either SWL or URS. Future efforts are needed to better align postoperative imaging practices with best practice guidelines.

MP07-18 Observation of radiopaque renal lesions

A Keln, S Schmidt, DG Alifov

Tyumen State Medical University

Introduction & Objective: Every year, 403.3 thousand new cases of kidney cancer and 175.1 thousand deaths from this pathology are registered in the world. More than half of the patients are over 65 years old at the time of diagnosis. Most primary kidney tumors are diagnosed incidentally as asymptomatic small <4 cm tumors. These tumors have a high degree of differentiation and rarely require surgical treatment, and if the operation is performed, the data of the pathomorphological result are benign. Due to the slow progressive growth and asymptomatic course, the method of dynamic observation of kidney tumors avoids unnecessary risks of surgical treatment. Trace the growth rate of renal tumors that accumulate contrast agent.

Methods: In the period from 2009 to 2019, all cases of radiographically confirmed renal masses were collected. Researched 50 people aged from 58 to 90 years. The study group included patients with renal neoplasms ≤7 cm in size. CT scan was performed on a regular basis, every 3 to 6 months, to assess the dynamics of growth. The diameter of the tumor in the largest dimension was taken as the size of the tumor. The tumor growth rate was calculated as the average change in diameter for 1 year during the entire observation period.

Results: The average age of the patients was 74.8 ± 7.4 years. The average tumor size at the time of detection was 35.0 ± 6.9 mm. The average linear tumor growth rate was 6.6 ± 2.4 mm / year. Tumor size at the time of diagnosis did not correlate with growth rates (p > 0.05). No dependence was revealed of the rate of increase in the size of formations depending on their structure ‐ solid (median 6 mm / year; average ‐ 10 mm / year) or cystic solid (median 7 mm / year; average 9 mm / year; p > 0.05 ). The absence of the dynamics of tumor growth during the entire observation period was revealed in 22 people.

Conclusions: Most malignant kidney tumors have a slow growth rate. This conclusion allows us to take a differential approach in the choice of surgical treatment, which is optimal for elderly patients with low somatic status.

MP07-19 Percutaneous Image Guided Cryoablation and Radio‐frequency Ablation versus Partial Nephrectomy for small renal cell carcinomas: a ten‐years, single centre observational study

V Vinson, F Osman, J Cartledge, M Kimuli, N Vasudev, C Ralph, S Jagdev, S Bhattarai, J Smith, J Lenton, T Wah

School of Medicine, Faculty of Medicine and Health, University of Leeds, Leeds Department of Targeted Intervention, Division of Surgery and Interventional Science, University College London, London

Introduction & Objective: There is a lack of long‐term evidence supporting the non‐inferiority of cryoablation (CRYO) and radio‐frequency ablation (RFA) when compared to partial nephrectomy (PN) for the management of small renal cell carcinomas (RCCs). This is the first‐ever study to report 10‐years long‐term evidence comparing CRYO or RFA and PN for the management of small RCCs.

Methods: Following institutional health and research authority approval, all patients in the prospective registry (2004‐2015) with a solitary, biopsy‐ or histology‐proven T1N0M0 sporadic RCCs had RFA, CRYO or PN were included in this retrospective analysis. The primary outcome is 10‐years cancer‐specific survival (CSS). Secondary outcomes include overall survival (OS), local recurrence‐free survival (LRFS), metastasis‐free survival (MFS), complication rates and change in renal function pre‐operatively and post‐operatively. Survival outcomes are evaluated using the Kaplan‐Meier method and Cox Proportional‐Hazards Model, while complication rates and change in renal function are evaluated using logistic regression and linear regression, respectively.

Results: A total of 296 patients (187 males, 109 females) with a median [IQR] age of 68 [16] years. Median tumour sizes for CRYO (3.3 [1.6]), RFA (3 [1.1]) and PN (2.7 [1.3]) are similar. Amongst them, 239 (81%) had T1a disease, and 57 (19%) had T1b disease. The median follow‐up periods are 75.5 [26], 99.4 [74] and 71.7 [32] months for CRYO, RFA and PN group, respectively. A total of 104 (35%), 99 (34%) and 93 (31%) of patients had CRYO, RFA and PN, respectively. CRYO and RFA are similar to PN in all oncological outcomes (Table). Both the rates and severity of complications did not differ between the three groups. Using linear regression model, the predicted eGFR reduction of T1a patients are smaller in CRYO (8.0%) and RFA (12.4%) patients when compared to PN patients (p < 0.01). Similarly, in T1b patients, predicted eGFR reduction is 16.5% and 22.2% smaller in those undergoing CRYO and RFA, respectively compared to PN patients.

Conclusions: Our long‐term experience found CRYO and RFA to be similar to PN for oncological outcomes and potentially superior for peri‐operative outcomes in T1a RCC patients; and should be considered as a first‐line treatment. More data is needed to evaluate the efficacy of ablative therapies for T1b tumours.

MP07-20 Withdrawn

MP07-21 A Novel CO2‐Digital Subtraction Nephrostogram Imaging Technique For “Contrast‐free” Percutaneous and Retrograde Endoscopic Renal Surgery in the Severely Contrast Allergic Patient

AJ Hannemann, MD Sawyer, E Ballon‐Landa, SD Herrell, J Eun

VA ECHCS/University of Colorado School of Medicine

Introduction & Objective: Use of iodinated contrast in endoscopic urology cases even with recognized allergy is generally considered low risk. However, there is potential for extra‐luminal exposure from pyelo‐venous back flow or contrast extravasation.

A severely debilitated paraplegic patient with numerous allergies was referred for recurrent severe UTIs. CT scan demonstrated >2 cm stone burden with Hounsfield units consistent with struvite. She elected definitive treatment with percutaneous nephrolithotomy. This patient reported a prior severe anaphylactoid reaction with IV contrast despite steroid premedication.

Carbon dioxide (CO2) angiography has an established role in endovascular surgery in setting of nephropathy or iodinated contrast allergy. We describe a novel adaptation for endoluminal imaging to avoid contrast in a two‐stage treatment.

Methods: “Contrast‐free” Micro‐PCNL was successfully performed in a hybrid OR. Percutaneous renal access was obtained by Urology with ultrasound guidance using retrograde methylene blue instillation. A 12/14 French ureteral access sheath was advanced percutaneously. The surgery was performed using a Lithovue disposable ureteroscope with holmium laser and extensive stone basketing. Indications for micro‐PCNL were anemia and facilitation of healing given thin parenchyma.

CO2‐nephrostogram was performed using arterial pressure tubing connected to the sheath. Digital subtraction imaging was obtained with biplanar fluoroscopy as gas was injected. This outlined the renal pelvis, calyces and proximal ureter and confirmed interpolar positioning of the access sheath. In a second stage procedure, retrograde CO2‐pyelogram was obtained in a standard OR.

Results: No iodinated contrast was used in either procedure. The patient tolerated each well without complications. Digital subtraction imaging technique was successful with biplanar and traditional fluoroscopy. Adequate imaging of the renal pelvis and calyces was achieved without the use of traditional contrast media.

Conclusions: CO2 is a non‐nephrotoxic and non‐allergenic alternative to contrast for endovascular angiograms, when iodinated contrast is contraindicated. We report a novel, safe, and easily reproducible adaptation to obtain upper tract imaging. This facilitated performance of two complex endoscopic urologic surgeries without using iodinated contrast in a highly allergic patient.

MP07-22 Novel 3D Anatomical Modeling Facilitates Laparoscopic or Robotic Donor Nephrectomy in Patients with Complex Renal Anatomy that were Precluded from Donation based on Computed Tomography Angiography or Magnetic Resonance Imaging

J Kuo, N Velazquez, M Degen, R Munver

Hackensack Meridian School of Medicine

Introduction & Objective: In the setting of complex renal anatomy, patients may not be considered suitable candidates for donor nephrectomy due to concerns of surgical complexity for the donor and recipient surgeons. We describe the use of IRIS^™ (Intuitive Surgical, Inc) segmented three‐dimensional (3D) anatomical modeling for preoperative planning and intraoperative navigation to facilitate laparoscopic or robotic donor nephrectomy. This technology delivers a 3D model of kidney anatomy that is created from CT scan imaging with maximum 3 mm slice width. The images are delivered to an iOS device and can be displayed via a hardwire connection from the iOS device to the robotic surgical console.

Methods: Since June 2020, a total of 28 potential living renal donors underwent preoperative computed tomography angiography (CTA) as part of the routine evaluation. In addition, segmented 3D modeling was performed for all patients based on the CTA images, highlighting the renal anatomy, arterial and venous vasculature, collecting system, and ureteral course. The CTA and 3D models were reviewed by the living donor and recipient teams for those patients with complex renal anatomy to further assess the candidacy of the renal donors.

Results: Three of the 28 patients (10.7%) were not considered to be suitable candidates for renal donation based on CTA or magnetic resonance imaging findings of renal abnormalities, including 3 renal arteries bilaterally (n = 1), 3 right renal arteries and 2 left renal arteries with a circumaortic left renal vein (n = 1), and a right 3 cm perirenal mass of unclear origin in the area of the renal hilum (n = 1). Following review of the 3D anatomical reconstructed images, all patients were cleared to undergo donor nephrectomy based on the additional information that was provided from these images. In the patient with the perihilar mass, the 3D imaging delineated the mass as arising from the renal parenchyma. This patient underwent robot‐assisted donor nephrectomy with ex‐vivo excision of the mass (pathology: lipid‐poor renal angiomyolipoma), with successful subsequent renal transplantation. The other 2 patients underwent uneventful left laparoscopic donor nephrectomy. There were no complications in the renal donors or recipients.

Conclusions: 3D anatomical modeling with IRIS^™ allows surgeons to perform donor nephrectomy in patients that may otherwise be excluded from renal donation. This technology offers preoperative interpretation of renal anatomy, provides confidence in the setting of complex vasculature, and facilitates planned procedural completion.

Video Session

V01: percutaneous surgery

RK Jain, J Bjazevic

V01-02 Mini‐PCNL for multiple Hem‐o‐lok clips forming stone nidus in the collecting system

T Aro, A Rai, D Hoenig, AD Smith, Z Okeke

Introduction & Objective: With the advancement of technology and medicine, minimally invasive surgery became the standard in many fields. Laparoscopic and robot assisted laparoscopic surgery is the preferred surgical treatment for renal masses, and Percutaneous NephroLithotomy (PCNL) is the standard of care for large renal calculi. And more and more frequently we are encountering patients with both conditions.

Methods: We present a case of a patient undergoing mini‐PCNL for nephrolithiasis, one year following robotic assisted laparoscopic partial nephrectomy. Computed Tomography (CT), Magnetic resonance (MRI), and Flouroscopy imaging are provided, as well as live video of the mini‐PCNL.

Results: The video demonstrates a total of three hem‐o‐lok clips found inside the collecting system, constituting a nidus for stone formation.

Conclusions: Although we do not fully understand the mechanism of clip migration, it has been demonstrated in several previous case reports. We present a rare case of multiple clips migration into the collecting system. We should always be suspicious of migrated hem‐o‐lok clips as a nidus for stone formation in patients following robotic or laparoscopic surgery.

V01-03 Bilateral Nephrolithiasis And Upper Tract TCC in Horseshow Kidney

T Aro, A Rai, D Hoenig, AD Smith, Z Okeke

Introduction & Objective: Nephroureterectomy is the gold‐standard treatment for High grade Upper tract urothelial carcinoma to date. Current guidelines and expert opinions offer some exceptions to this based on patient characteristics, disease status, and the contralateral kidney.

Methods: We present a rare case of a patient with horseshoe kidney, bilateral large nephrolithiasis, high‐grade upper tract urothelial carcinoma in one moiety, and relative parenchymal thinning of the contralateral side. The patient was treated in a percutaneous minimally invasive, nephron sparing approach. Computed Tomography (CT) and Fluoroscopy images are provided, as well as live video of all procedures.

Results: Videos of multiple procedures are provided to demonstrate percutaneous resection of the tumor, stone lithotripsy, and repeat biopsies. The patient also had Intra collecting system instillations of gemcitabine and docetaxel, and video of post‐installation percutaneous flexible nephroscopy is provided.

Conclusions: Minimally invasive percutaneous resection of high‐grade upper tract urothelial carcinoma is a safe procedure in select cases. Current guidelines may not apply to all patients; unique scenarios with upper tract urothelial carcinoma may require personalized decision making and treatment at specialized centers.

V01-04 Gradual Percutaneous Nephrolithotomy For Complete Staghorn Stone Can Facilitate Renal Access, Prevent Complications And Improve Stone Free Rate

J Feghali

Introduction & Objective: Standard Percutaneous nephrolithotomy (PCNL) is the gold standard for the treatment of renal stones larger than 2cm. when treating full staghorn calculi; urologists encounter difficulty while creating renal tract due to limited space in the pyelocaliceal system around the stone, and difficulty to bypass the stone and insert a wire down the ureter. Objective: evaluate a new technique called gradual PCNL defined as treating large stones in single procedure by MiniPCNL followed by standard PCNL through the same tract In order to reduce complications, perform the ideal tract; and improve the Stone Free rate (SFR)

Methods: During 2019, five men with mean age of 59 years old, and complete staghorn stones were treated with Gradual PCNL technique by single surgeon . Ureteral occlusion balloon catheter 34fr/100cm was placed in lithotomy position in order to dilate the pyelocaliceal system; followed by renal punction in prone position via an 18 gauge needle under fluoroscopic and/or ultrasound guidance. A 0.035 inch hydrophilic tip wire was then inserted in the pyelocaliceal system ; followed by MiniPCNL technique in order to confirm appropriate punction , prevent traumatic dilation; open a stone window by laser or pneumatic lithotripsy and insert the wire down the ureter. Once the wire has reached the bladder, we removed the MiniPCNL operating sheath (15/18Fr) and dilated the same tract with nephrostomy balloon catheter 30 Fr , then we switched to standard PCNL (using nephroscope sheath24 Fr) and removed the stone with ultrasonic lithotripsy. At the end of procedure a 7Fr/28cm ureteral stent was placed in an antegrade fashion, and 20 Fr nephrostomy tube was left in place.

Results: Mean Gradual PCNL operation time was 130.2 minutes; mean fluoroscopy time was 4.2min; Nephrsotomy tube was removed on day 1, all patients were discharged 48 hours after procedure ; no blood transfusion was needed ; mean Hemoglobin drop after surgery was 1.38g/dl; no major postoperative complications; SFR was 80% 1 month after surgery

Conclusions: Gradual PCNL for complete Staghorn Stone is a single procedure that can facilitate renal access, prevent complications and Improve Stone Free Rate

V01-05 Supine Percutaneous Nephrolithotomy (PCNL) in Horseshoe Kidney

MO Breish, S Sriprasad, D Whiting, F Anjum, O Abdalla

Introduction & Objective: Horse‐shoe kidney (HSK) is the most common renal fusion anomaly, with reported incidence of 1:400 mainly in males (M: F = 2:1). Nephrolithiasis is frequently occurred in HSK patients with an estimated range of 21%‐ 60% due to ureteropelvic junction obstruction, urinary stasis, recurrent infections, and metabolic abnormalities. Percutaneous nephrolithotomy (PCNL) is a procedure of choice for a high stone burden in a HSK with overall stone free rate of 72 % to 93.1%, and usually performed while patient in a prone position. In this video we present a case of a supine PCNL performed in our institution to treat stones in HSK.

Methods: 59 years old gentleman known to have HSK presented with left sided abdominal pain and a past medical history of renal stones. Previously, he was treated for renal calculi using shock wave lithotripsy and ureteroscopy. Blood investigations showed normal kidney function, however non contrast CT KUB demonstrated multiple calculi within the left moiety of HSK. He was counselled to undergo supine PCNL to treat the stone burden. Intraoperatively, the patient was prepared and positioned in the lithotomy position in order to perform retrograde studies. An Occlusion balloon catheter was placed within the ureter. An upper calyx puncture was performed to access the left moiety of HSK. Both hydrophilic and extra stiff guidewires were passed into the lower calyx. the puncture needle was removed leaving the guidewires in place. Balloon dilatation was performed followed by placement 30F Amplatz sheath. Flexible nephroscopy was performed in order to identify and basket the stones out of the kidney. 16 F Malecot nephrostomy was placed and secured.

Results: 1‐2 days post operatively, the patient developed fever and was treated with Intravenous antibiotics. Post‐ operative CT KUB showed a patent nephrostomy in situ and confirmed stone free kidney. The nephrostomy was removed on day 7 and the patient was discharged 8 days post‐ operatively . The patient made a good recovery without major complications and was deemed stone‐free following supine PCNL.

Conclusions: Supine PCNL is therefore feasible and safe option to treat stones in patients with HSK.

V01-06 Percutaneous nephrolithotomy in challenging cases of renal stones

J Park, H Park, H Shin

Introduction & Objective: To report our surgical techniques of percutaneous nephrolithotomy (PNL) which were performed in challenging cases including calyceal diverticular, renal parenchymal stones, and renal pelvic impacted stone with multiple infundibular narrowing.

Methods: 42‐year‐old man (patient 1) and 48‐year‐old woman (patient 2) were referred for persistent right flank pain. The two patients had been treated with shock wave lithotripsy under diagnosis of renal calyceal stones at other hospitals, but not fragmented. The other patient, 49‐year‐old man (patient 3), visited outpatient clinic due to left flank pain that developed one year ago. After 3‐phase CT scans, the patients were diagnosed with 2.9 cm‐sized calyceal diverticular stone (patient 1), 2.2 cm‐sized renal parenchymal stone (patient 2), and 2.8 cm‐sized renal pelvic impacted stone with multiple infundibular narrowing (patient 3). The three patients were treated with PNL. Direct puncture into diverticulum and dilation of diverticular neck (patient 1), laser incision of parenchyma overlying stone (patient 2), and infundibulotomy (patient 3) was performed

Results: Patient 1 and 2 were completely stone‐free after PNL, while two third of stone burden of patient 3 was removed. The nephrostomy tube was removed at 4 to 5 days after surgery, and the patients recovered without specific complication. At postoperative 1 month follow‐up, patient 1 and 2 were symptom‐free, and patient 3's symptom much improved. On excretory urography, diverticulum size decreased while wide diverticular neck was identified (patient 1), and previous stone cavity was visualized with pelvocalyceal system (patient 2). In patient 3, residual stones were identified in upper pelvocalyceal system at follow‐up CT.

Conclusions: Though PNL represents a technically challenging procedure that requires specific endourologic skills, PNL has still advantage in treating patients with complex renal anatomy, such as calyceal diverticular stone, renal parenchymal stone, and infundibular narrowing.

V01-07 Encrustated Metallic Ureteral Stent Treated By Mini Percutaneous Nephrolithotomy

T Machado, R Astolfi, R Carrera, G Freschi, N Gattas, A Meller

Introduction & Objective: The use of polymeric double J stents for the management of ureteral strictures is effective for a short period of time, although they have limited use due to the risk of obstruction and to the need for periodic stent changes. Metal stents have been developed with the aim of maintaining greater ureteric patency, alleviating symptoms, and, especially, allowing less frequent exchanges. Although metallic stent changes are approved for 12 months, there are no concrete data defining a safe dwell‐time to prevent clinically significant encrustations. Likewise, there are no reports of surgeries performed to treat metal stent encrustations. Our objective with this video is to describe a case of a large metallic ureteral stent encrustation successfully treated by Mini Percutaneous Nephrolithotomy (MiniPerc) in an obese patient.

Methods: A 48‐year‐old female was admitted at our hospital for treatment. The patient had previously undergone a metallic DJ stent implantation for the treatment of a chronic ureteral stricture but hasn't had a stent exchange in the last 18 months due to loss of follow‐up. Radiological exams revealed a large encrustation at the right renal pelvis (2,5x1,6cm). After the attempt of removing the stent by cystoscopy failed, a mini percutaneous nephrolithotomy was performed to treat the kidney stone and to implant another stent.

Results: After the procedure, the patient became stone‐free and had a silicone DJ stent implanted. Metabolic evaluation of the urine did not reveal hypercalciuria or any other contributing factor for this severe complication.

Conclusions: Large encrustations on a metallic ureteral stent are rare complications and may require surgical treatment. Mini percutaneous nephrolithotomy seems to provide a safe and feasible treatment option for these cases, even in obese patients.

V01-08 Title: Endoscopic Combined IntraRenal Surgery (ECIRS) with SOLTIVE Laser and Mini‐PCNL Technique

S Niu, SM Alam, WR Molina

Introduction & Objective: Endoscopic Combined IntraRenal Surgery (ECIRS) is a combined rigid and flexible antegrade and retrograde approach for the treatment of large kidney stones and provides an opportunity to exploit the full array of endourologic equipment. As more urologists are adopting the mini‐percutaneous nephrolithotomy (mini‐PCNL) technique to decrease morbidity associated with conventional PCNL while preserving high stone free rates when compared to ureteroscopy, we aim to determine the feasibility and efficacy of ECIRS using the SOLTIVE^TM laser combined with mini‐PCNL for treatment of moderate sized renal stones.

Methods: After Institutional Review Board approval, we retrospectively reviewed two patients with stones between 1.5‐2.5cm who underwent treatment with ECIRS using simultaneous mini‐PCNL with SOLTIVE^TM laser and retrograde ureteroscopy. Access was obtained intraoperatively. We selected one of the cases to highlight our ECIRS experience using the novel combination of technology and technique.

Results: In modified supine position, the flank is elevated to create 15 degrees of rotation to expose the puncture area, demarcated by the 12th rib, iliac crest and posterior axillary line. The 15/16Fr rigid access sheath was used for access. The 365‐micrometer fiber achieved exceptional ablation rate and dusting with the setting of 1J and 36Hz. Simultaneous retrograde ureteroscopy facilitated mini‐PCNL by amplifying the vortex effect with maneuvers such as “pass the ball” technique. Neither patient had a postoperative complication, and both were considered stone free based on postoperative imaging. This is a descriptive video of our technique that has been performed on a total of 2 patients. No statistical analysis was calculated due to the rarity of this procedure.

Conclusions: ECIRS with SOLTIVE^TM laser and mini‐PCNL technique is a safe and effective strategy for treatment of stones with sizes that fall in between conventional PCNL or flexible ureteroscopy alone. The optimal wavelength of the SOLTIVE^TM laser created superior ablative properties which facilitated the performance of faster and more effective lithotripsy. Simultaneous retrograde ureteroscopy allowed for complete surveillance of the collecting system, relocation of stone fragments for ease of treatment, and amplification of the vortex effect. Further studies with larger cohorts are needed to assess the generalizability of our outcomes with this novel combination of technique and technology.

V01-09 Pediatric PCNL ‐ Past Challenges and Future Directions

C Ferari, C Crigger, M Ost, O Al‐Omar, O Al‐Omar

West Virginia University

Introduction & Objective: Pediatric percutaneous nephrolithotomy (PCNL) for large stone burden is an under‐utilized approach to stone removal in younger patients. This stems from the large instrumentation traditionally used interchangeably in adult and pediatric populations. Though large instrumentation has shown efficacy in pediatric patients, recent efforts to “miniaturize” the approach, and therefore the associated morbidities, have made PCNL more amenable in the pediatric patient.^1,2

Methods: Through the case of a 10‐month‐old female presenting with painless hematuria and a 10‐year‐old female with left flank pain and hematuria, both secondary to renal calculi, we present an overview of the challenges inherent to PCNL, the push for miniaturization, and examples of the preferred technique employed by fellowship trained pediatric urologists at our institution. Our 10‐month‐old female presented with painless gross hematuria and our 10‐year‐old female presented with left flank pain and gross hematuria. PCNL was chosen as the operative approach to remove their stone burden based on imaging (Figure 1, Figure 2).

Results: Complete removal of stone burden was achieved in both of our patients using mini‐PCNL tract sizes with no complications.

Conclusions: Our video highlights two cases of successful use of mini‐PCNL technique to remove stone burden in pediatric patients with no complications. A variety of smaller tract sizes for pediatric PCNL have been described over the last several decades, including mini‐PCNL (typically 14‐22 Fr), ultramini‐PCNL (typically 11‐13 Fr), and micro‐PCNL (typically 4.8‐10 Fr). A recent meta‐analysis concluded that miniaturized PCNL was at least as efficacious and safe and standard PCNL but had longer operating times.³ In demonstrating this technique that is currently actively evolving, we hope to shed some light on the exciting new trend in “miniaturized” PCNL and its applicability – with regard to efficacy and safety – in the pediatric population.

V01-10 Using 3D Scanning to Create a CNC Machined Polyurethane Bed for Patient Positioning During Percutaneous Nephrolithotomy

DC Fedrigon, S Sivalingam

Cleveland Clinic‐ Glickman Urological & Kidney Institute

Introduction & Objective: Nephrolithiasis is a cause of significant morbidity in patient populations with musculoskeletal abnormalities, spinal cord injury, and multiple sclerosis often requiring surgical intervention such as percutaneous nephrolithotomy (PCNL). Safely positioning patients with limb contractures or other musculoskeletal abnormalities in the prone position for PCNL can be a challenge intraoperatively and is an area that has not been previously explored in the literature. Therefore, we present a case report on the production and implementation of a custom foam bed designed from a 3D‐scan of a percutaneous nephrolithotomy patient with upper extremity contractures.

Methods: A female patient with a history of congenital hydrocephalus, seizures, developmental disabilities, and a left upper extremity permanently contracted across her chest was identified preoperatively as a candidate for a custom bed. Informed consent was obtained from the family in accordance with our institutional review board policies. Prior to surgery, a Microsoft Kinect V2 was used to 3D scan a patient with Meshmixer and Fusion 360 (Autodesk) being used to develop the 3D custom bed model. The model was then machined out of Airtex 5'' 160 oz High‐Density Foam using a ShopBot PRSAlpha 96x48 CNC machine with an Amana HSS1614 router bit.

Results: The custom foam bed was successfully utilized in place of traditional positioning padding in the operating room during the patient's surgery. The foam bed was used to cushion the patient's upper body during the prone split leg procedure while appropriately relieving pressure on the patients arm that needed to be positioned across her chest.

Conclusions: We report a novel use for custom contoured polyurethane beds in the operating room and we demonstrated a reproduceable workflow for a 3D‐scanning and CNC milling production process. The custom bed performed as expected within the operating room, providing both easy prone positioning and adequate cushioning for the patient's contracted upper limb. This technique is reproducible with equipment accessible to most academic care centers and has applications across multiple surgical disciplines that commonly utilize prone positioning such as endourology and spinal surgery.

V01-11 Thulium laser dusting of a partial staghorn stone via 14Fr Super‐mini percutaneous approach – technique and optimal laser settings

E Edison, T Reid, R Vitale, N de Luyk, V Arumuham, C Allen, S Choong

Introduction & Objective: The capability of Thulium Fibre Laser (TFL) lithotripsy to dust stones compliments the continuous suction of Super‐mini percutaneous approach (SMP) in treating kidney stones. Compared to Holmium:YAG, TFL can deliver more power, through smaller fibres, with a wider range of energy, frequency and pulse length parameters, with higher water absorption and more efficient stone ablation. Thus TFL is an excellent novel technique for SMP lithotripsy. The objectives of this video are to demonstrate use of TFL via SMP for a partial staghorn, and by varying the energy, frequency and pulse duration, to demonstrate optimal laser settings.

Methods: Video is recorded from the 14Fr SMP of a partial staghorn cystine stone, 3.5 x 2.5 cm (650 HU). SMP access was obtained with ultrasound and fluoroscopic guidance and serial dilation to 14Fr. A 14Fr 13cm ClearPetra sheath and a 7.5Fr Storz Nephroscope was used, with a 365μm TFL (Olympus Soltive). There was continuous irrigation through the scope, and independently controlled continuous suction through the sheath. Modifiable parameters of energy (0.025 to 6J) and frequency (1 to 2400Hz) are available in combinations up to maximum power of 60w. Pulse duration is short, medium or long (200μs to 50ms). Various laser settings are demonstrated and evaluated.

Results: With a total laser time of 22 minutes, delivering 71.01kJ, the kidney was clear of stone on direct vision and fluoroscopy. A ureteric stent was left, with no nephrostomy. The patient was discharged on the same day with no complications. Follow up CT at 1 month demonstrated a 3mm interpolar calcification. Relook ureterorenoscopy during stent removal demonstrated this to be parenchymal. The optimal laser setting was found to be 0.6J / 100Hz / long pulse. This allowed for rapid, efficient stone dusting with fine fragments large enough for stone analysis. Higher frequencies involved extremely fine dusting which was slower. Some settings (as seen on video) induced large amounts of bubbles that obscured the view. These findings are corroborated by the authors' experience in other patients.

Conclusions: Thulium fibre laser lithotripsy allows for safe, rapid stone dusting. Super‐mini access allows for continuous irrigation and suction to maintain views, dissipate heat, and maintain low renal pelvic pressure, enabling uninterrupted lasering. The convergence of these technologies means that larger stones and partial staghorns can be managed safely and effectively as a day case procedure.

Moderated Poster Session

MP08-01 Robotic Repair of Ureteroenteric Strictures after Urinary Diversion

MW Salkini, A Dahman

West Virginia University

Introduction & Objective: Ureteroenteric strictures develop in up to 20 % of patients after urinary diversion. The surgical revision of the anastomosis is challenging and needs large midline incision due to the adhesions and scarring following urinary diversion. We are reporting on the outcome of robotic repair of ureteroenteric strictures after urinary diversion

Methods: Nine patient presented to our service with anastomotic stricture of the Ureteroenteric anastomosis after urinary diversion. Two patient presented with left ureteral anastomotic structure to ileal neobladder. The remaining seven presented with ureteroenteric structure at the ileal conduit. 3 patients had bilateral ureteral anastomotic stricture, 2 right sided stricture of a solitary kidney and 2 patient had isolated left ureteral anastomotic stricture.

Results: The average patients' age at presentation was 72 years (range 59‐82) with 2 females (22 %). All cases were done robotic with no conversion. The average length of the procedures was 201 min (90 min‐ 460). An average blood loss of 183 ml (50‐800). The average hospital length of stay was 4.2 days (1‐14). 2 patient developed transient ileus that resolved with no intervention. One patient had DVT (11%) after surgery, and another had AKI (11%). All the anastomosis were open after follow up of 28 months (18 – 44). None of the patient progressed to chronic renal failure or needed dialysis.

Conclusions: Robotic ureteral anastomotic repair is viable option for ureterointestinal anastomotic structure. The robotic approach minimize the invasiveness of the procedure with good outcome. Longer follow up is needed to insure the reliability of the technique.

MP08-02 Cutaneous Ureterostomy or Ileal Conduit urinary diversion: Can we spare the bowel following Radical Cystectomy in patients with solitary functioning kidney?

B Nayak, S Saini, P Singh, R Nayyar

All India Institute of Medical Sciences, New Delhi

Introduction & Objective: To compare the outcomes following radical cystectomy in a group of patients with a solitary functioning kidney who either underwent cutaneous ureterostomy or ileal conduit urinary diversion.

Methods: We retrospectively analyzed clinical records of patients with a solitary functioning kidney who underwent radical cystectomy at our institute between Jan 2014 and May 2019. We included patients who either received cutaneous ureterostomy or ileal conduit urinary diversion. Baseline characteristics, perioperative outcomes including complications encountered and final histopathological stage were evaluated, and compared between the two groups. For the assessment of renal function outcomes, we only included the patients with a follow up for at least 2 years.

Results: A total of 43 patients were included in the comparative analyses. Of these, 23 & 20 patients underwent cutaneous ureterostomy & ileal conduit diversion, respectively. The two groups were similar concerning baseline demographic and clinical characteristics. Operating time (p < 0.001), time to drain removal (p = 0.016), postoperative length of hospital stay (p = 0.018) and bowel‐related complications (p = 0.047) were significantly higher in patients who underwent ileal conduit diversion. Although, the eGFR was comparable between the two groups at baseline, at 6 months, and at 1 year of follow up. There was a greater decline in eGFR at 2 years of follow up in patients who received cutaneous ureterostomy (p = 0.039).

Conclusions: The present study shows that cutaneous ureterostomy has better perioperative outcomes, including postoperative complications and comparable short term renal function outcomes over ileal conduit urinary diversion. However, over two year follow up there was an increased likelihood and greater degree of decline in eGFR in patients who received cutaneous ureterostomy.

MP08-03 Approach to management of uretero‐vaginal fistula: Review of 15 cases over 10 years

P Singh

All India Institute of Medical Sciences, New Delhi, india

Introduction & Objective: The prevention and management of gynaecological fistula always remains a big challenge. The rate was highest among women who had hysterectomy following cervical cancer. Isolated ureterovaginal fistula is rare. Patient can present lately with poorly functioning of kidney. So early diversion or corrective surgery is warranted in this condition. Most common site involved is lower ureter. The aim of this study is to describe our experience of management of iatrogenic uretero‐vaginal fistula resultant of gynecological surgery and obstructed labour over a span of 10 years and outcomes

Methods: We reviewed our database from 2009 ‐2019 and followed up this cohort of patient prospectively for outcomes.

Results: : A total of 15 patients with uretero‐vaginal fistula were identified. None of this cohort of patients had concurrent vesico‐vaginal fistula. Mean age of patient was 39 years. All patients presented with continuous urine leak with normal voiding in between. Five patients had laparoscopic hysterectomy, 7 underwent open transabdominal hysterectomy (caesarean hysterectomy for hemorrhage), 3 underwent transvaginal hysterectomy. Mean time to develop symptoms was 5 days after surgery. Mean time to discharge after primary surgery leading to iatrogenic fistula was 17 days. Time from fistula to corrective surgery was 9 months (1 month‐3 years). 14 patients had percutaneous nephrostomy placed prior to surgery as a diversion measure. Kidney function was preserved in all patients. Before definitive surgery, check cystoscopy to rule out vesicovaginal fistula and nephrostogram was done in all patients. 13 patients underwent open extraperitoneal ureteroneocytostomy. 2 out of 13 patients needed Boari reconstruction as an adjunctive to ureteroneocystostomy. 1 patient underwent robot assisted and 1 underwent laparoscopic ureteroneocystostomy (transperitoneal). All the procedures used modified Lich‐Gregoir technique for ureteric reimplantation. 1 patient was treated with just DJ stenting. Urethral catheters were removed at a mean of 10 days and DJ stents were removed at a mean of 5 weeks. Mean follow up of patient is 5 years (1‐10 years). None of the patient had recurrent symptoms and all the patients are completely dry at present.

Conclusions: Ureterovaginal fistulae are complicated by virtue of their cause and can be well managed by minimally invasive or open surgery. At times Psoas hitch or Boari reconstruction is warranted.

MP08-04 Withdrawn

MP08-05 Organ‐sparing surgery with Bracka's reconstruction for penile cancer: a single‐center experience

A Gallioli, A Rosales, JM Gaya, A Sánchez‐Puy, A Piana, P Diana, A Territo, P Gavrilov, J Caldéron, J Palou, A Breda

Department of Urology, Fundació Puigvert, Barcelona, Spain

Introduction & Objective: Penile cancer is a rare disease requiring a dedicated team to perform a patient‐tailored treatment. The crucial point to avoid local recurrence or progression of the disease is to achieve radicality. Classic surgical approach, based on the belief that a 2 cm surgical margin is needed to guarantee negative surgical margin, consists in partial or total penectomy with closure of the penile stump using a skin graft drown from the shaft. This technique carries aesthetical and psychological dysfunctions which can be reduced with less mutilating approaches without compromising the oncologic outcome. The aim of this study was to assess the outcomes of organ‐sparing surgery with Bracka's reconstruction.

Methods: In this retrospective analysis carried out from our prospective penile cancer database, we evaluated patients who underwent penile‐sparing surgery with Bracka's technique from 2002 to 2020 in our center. The technique includes the harvesting of a rectangular piece of medium‐thickness split‐skin graft of the upper outer aspect of the thigh. The graft is fixed to the distal part of penis and the meatus with 6/0 Vicryl Rapide suture to create the neo‐glans. Demographic variables, perioperative data, surgical and oncological outcomes were analyzed.

Results: 30 patients were included, with a median (IQR) age of 62 (12) years. 14 (46,6%) patients underwent total glansectomy, 10 (30%) glans demucosation, 5 (16,6%) partial penectomy, 1 (3,3%) partial penectomy with glans preservation. Mean operative time was 172 minutes. Absence of intraoperative complications. At the final pathological examination, 6 (20%) patients were diagnosed squamous cell carcinoma pT1, 13 (43,3%) pT2, 3 (10%) pT3, 7 (23,3%) PeIN and 1 (3,3%) pT0, with grade G1 in 10 (33,3%) patients, G2 in 11 (36,6%) and G3 in 6 (20%). Median follow‐up was 37 months (88). In 14 (46,6%) cases perioperative Clavien Dindo I and II complications were reported. 6 (20%) patients suffered from partial graft necrosis, treated conservatively. No local recurrence was observed. Lymphatic progression occurred in 1 (3,3%) case of pT2G2 tumor with negative sentinel lymph node after 58 months from surgery. 2 (6,6%) urethral neo‐meatus stenosis occurred treated in 1 case with surgical reconstructive meatoplasty, and in the other with periodic urethral dilations was started 7 months after surgery.

Conclusions: Organ‐sparing surgery with Bracka's reconstruction for penile cancer is a suitable and oncologically safe approach. It provides good phallic length preservation along with a neo‐glans reconstruction without compromising the urinary function.

MP08-06 Uretero‐enteric Anastomotic Stricture Following Robotic Radical Cystectomy: Extracorporeal versus Intracorporeal Approaches in the Indocyanine Green Era

MB Tuna, T Doganca, OB Argun, I Tufek, SM Keskin, C Obek, AR Kural

Acibadem Maslak Hospital, Department of Urology

Introduction & Objective: The aim of the study is to compare the early period(6^th week after the catheter removal) iatrogenic benign uretero‐enteric anastomotic stricture formation between robotic radical cystectomy with intracorporeal urinary diversion, robotic radical cystectomy with intracorporeal urinary diversion(without utilizing ICG) and robotic radical cystectomy with intracorporeal urinary diversion(with utilizing ICG)

Methods: A total of 30 patients(59 renal units) who underwent robotic radical cystectomy with intracorporeal and extracorporeal urinary diversion between 2014‐2021 in our clinic included in our study. We retrospectively reviewed the demographic and perioperative results. The primary endpoint of our study was postoperative stricture rate 6^th after the catheter removal; suspicious of uretero‐enteric stricture formation.

Results: From our study cohort; 13 of these patients(26 renal units) underwent robotic radical cystectomy with Extracorporeal intracorporeal urinary diversion, 10 of these patients(20 renal units) underwent robotic radical cystectomy with intracorporeal urinary diversion(without utilizing ICG) and 7 of these patients(13 renal units) underwent robotic radical cystectomy with intracorporeal urinary diversion(with utilizing ICG). The overall incidence of early period uretero‐enteric stricture formation(was post‐operative 6^th week after the catheter removal) was 8.5%(5 renal units); 11,5% (3 renal units) after extracorporeal approach; 10%(2 renal units) after intracorporeal approach. None of the patients with intracorporeal approach with utilizing ICG had demonstrable uretero‐enteric strictures post‐operative 6^th week after the catheter removal.

Conclusions: In the ICG era; robotic cystectomy with intracorporeal diversion is a promising approach in terms of benign uretero‐enteric stricture formation when compared with robotic cystectomy with extracorporeal urinary diversion and intracorporeal urinary diversion without utilizing ICG. Larger prospective studies are required to confirm our outcomes.

MP08-07 Ureteral bypass: a new technique for the treatment of ureteral atresia

X Gao, J Chen, W Wang, X Wei

Department of Urology, Institute of Urology (Laboratory of Reconstructive Urology), West China Hospital, Sichuan University, Chengdu, Sichuan, P.R. China.

Introduction & Objective: Ureteral bypass is a new surgical technique for the treatment of ureteral atresia, including two surgical types. Under ureteroscopy, if a thick layer of fat is found between the ureteral atresia and the outer fascia, use a holmium laser to burn the fat to create a small channel (Figure 1A, 1B). If the ureteral atresia is closely adhered to the outer fascia, the atresia scar is directly burned to establish a channel (Figure 2A, 2B). The aim of this study was to assess the safety and effectiveness of ureteral bypass in treatment of ureteral atresia.

Methods: Between January 2019 to June 2020, 16 patients with ureteral atresia and were performed with ureteral bypass were included in this study. Ureteral bypass includes three key steps. First, the holmium laser endoureterotomy to establish a small channel (Figure 1B, 2B). Then, the balloon dilatation to create a large channel (Figure 1C, 2C). Finally, the Allium stent was inserted (Figure 1D, 2D). Prospective collection of indicators such as hydronephrosis volume, serum creatinine, urea nitrogen, operative time, hospital stay time, operative complications. Compare the changes in these indicators before and after surgery.

Results: During a median follow‐up time of 12 months (range 6–16 months), the success rate of ureteral bypass surgery is 93.75% (15/16). The median operative time is 78 minutes and median hospital stay time is 7.5 days. The incidence of pain is 25% (4/16), and the incidence of fever is 6.25% (1/16). Preoperative hydronephrosis volume (18.81 + 15.32 mm3) reduced postoperatively (16.52 + 34.81 mm3). Urea nitrogen level decreased from preoperatively (5.77 + 1.28 mmol /L) to postoperatively (5.26 + 1.61 mmol /L). Blood creatinine did not change significantly before and after surgery.

Conclusions: This shows that ureteral bypass is a safe and effective surgical method for ureteral atresia.

MP08-08 Retroperitoneoscopic pyeloplasty for primary UPJ obstruction in Horseshoe kidney: Experience of a tertiary care center from Northern India

V Singh, RJ Sinha, G Singh

Dept of urology, King George Medical University

Introduction & Objective: Primary UPJ obstruction (UPJO) is seen in 30% Cases of Horseshoe kidney. Retroperitoneoscopic pyeloplasty is less reported for surgical management of UPJO in such cases. We report our experience of performing classical retroperitoneoscopic pyeloplasty in 6 cases of Horseshoe kidney.

Methods: All cases of horseshoe kidney with unilateral primary UPJO who were operated by retroperitoneoscopy from 2013 to 2019 were included. Ultrasound (USG) kidney, ureter and bladder (KUB) and contrast CT Scan KUB were performed in all cases and revealed findings suggestive of primary UPJO. DTPA renal scan revealed obstructed system in all cases. Classical retroperitoneoscopic dismembered pyeloplasty was performed over a 6 F/26 cm DJ stent in all cases with 3 port technique. The DJR was performed after 6 weeks. A renal USG and DTPA scan at 2 weeks following stent removal were performed in all cases.

Results: The mean age was 18 years and all were male. Left to right ratio was 4:2. Pain was the predominant symptom. Total six cases were operated and mean operative time was 150 ± 30 minutes. The mean blood loss was 75 ± 20 ml, mean tramadol requirement for pain control during hospital stay was 125 ± 25 mg. The mean hospital stay was 2 days. No immediate postoperative complication occurred. The success rate of pyeloplasty is 100% till last follow‐up. None of the patient developed any long term complication in mean follow‐up of 36 months.

Conclusions: The classical retroperitoneoscopic pyeloplasty for primary UPJ obstruction shows excellent surgical outcome with no complication in long term follow‐up.

MP08-09 Laparoscopic Boari Flap for the management of long segment ureteral defect: Long term follow‐up

V Singh, RJ Sinha, G Singh

Dept of urology, King George Medical University

Introduction & Objective: The incidence of ureteral stricture is showing a rising trend due to increased use of laparoscopic and upper urinary tract endoscopic procedures. Boari flap is the preferred method of repairing long segment ureteral defects of 8‐12 cm. The procedure has undergone change from classical open surgery to laparoscopic surgery and recently robotic surgery. Laparoscopic repair is cosmetically appealing, less morbid and with shorter hospital stay.

Methods: This prospective study was conducted from 2016 to 2019. The patients with a long segment ureteral defect (8‐12 cm) were included. IVU was performed in 2 cases and CT urogram in 3 patients. DTPA scan was performed in all cases. Transperitoneal laparoscopic repair with 3 ports were performed in all cases.

Results: The procedure was performed in 5 cases with male to female ratio of 3:2. All had unilateral stricture. The mean stricture length was 8.8 cm (8.2 – 9.8cm). The mean operating time was 206 minutes (190‐230 minutes). The average estimated blood loss was 100 ml (9‐120 ml) and mean hospital stay was 6 days (5 to 7 days). The mean follow‐up was 22 months (19–32 months). None of the patient had any postoperative complications. DTPA scan was performed in all cases at 3 months in all cases.

Conclusions: Laparoscopic ureteral reimplantation with Boari flap is safe, feasible and has excellent long term results. However, the procedure is technically challenging, requires extensive experience of intracorporeal suturing.

MP08-10 Reconstruction of obliterated ureteral strictures is associated with increased difficulty

RA Lee, Z Lee, AM Asghar, D Strauss, R Harrison, N Cheng, LC Zhao, M Stifelman, DD Eun

Lewis Katz School of Medicine ‐ Temple University Hospital

Introduction & Objective: There is currently a paucity of literature evaluating predictors of increased difficulty for ureteral reconstruction. Herein, we evaluate whether stricture patency (ie. obliterated versus narrowed) affect the difficulty of ureteral reconstruction.

Methods: The multi‐institutional Collaborative of Reconstructive Robotic Ureteral Surgery (CORRUS) database was queried for patients who underwent ureteral reconstruction from June 2012 to February 2019. Strictures were identified as obliterated versus narrowed. Patients with obliterated strictures were defined as those unable to be traversed with contrast or an endoscopic guidewire. We utilized operating time (OT), estimated blood loss (EBL), and frequency of utilization of adjunctive mobility procedures (downward nephropexy, psoas hitch) as surrogates for procedure difficulty. Surgical success was defined as the absence of flank pain and the improvement or absence of obstruction on renal scan.

Results: A total of 361 patients presented for surgical management. A total of 55 obliterated strictures and 206 narrowed strictures were identified. There was no difference in stricture length between two subsets (P = 0.162). Obliterated strictures had significantly longer OT when located in the proximal/mid ureter(239 vs 160 min, P = 0.002 and 278 vs 190 min, P = 0.05, respectively). The EBL was slightly higher with proximal/mid ureteral reconstruction (100 vs 50 cc, P = 0.005). Reconstruction of obliterated strictures at the proximal/mid ureter required significantly more adjunct mobilization procedures, 32% vs 14.7% (P = 0.029). Obliterated strictures at the proximal/mid ureter had significantly increased major complications (24% vs 7.9%, P = 0.01), but the clinical and radiographic success rates remained similar regardless of location (P = 0.3 and P = 0.94).

Conclusions: We demonstrate that reconstruction of obliterated proximal and mid ureteral strictures are associated with increased complexity and likelihood to utilize adjunct mobilization procedures. Despite the increased complexity, success rates of obliterated strictures are similar to narrowed strictures. Defining stricture patency aids in preoperative planning and managing intraoperative expectations. No differences were seen when managing distal ureteral strictures.

MP08-11 Ureteral Reimplantation without Anti‐reflux Technique for Iatrogenic Ureterovaginal Fistula: Open Surgery vs. Laparoscopic Repair

Q He, D Luo, K Wang

Department of Urology, Institute of Urology （Laboratory of Reconstructive Urology）, West China Hospital, Sichuan University, Chengdu, Sichuan, P.R.C

Introduction & Objective: To show the safety and efficacy of the mucosa‐to‐mucosa anastomosis in ureteroneocystostomy without anti‐reflux technique, and to compare the therapeutic outcome between laparoscopic repair and open surgery using same procedure principles for iatrogenic ureterovaginal fistula.

Methods: A retrospective cohort study was conducted at a high‐volume referral hospital. 87 female patients, previously diagnosed with ureterovaginal fistula, underwent ureter reimplantation between 2008 and 2018. Those patients were contacted and underwent a follow‐up examination. The modified ureteroneocystostomy (mucosa‐to‐mucosa anastomosis without anti‐reflux technique) was conducted to restore urinary continuity. Vesicoureteric reflux was assessed by voiding cystogram, and effectiveness and safety in the laparoscopic repair group and open surgery group were compared.

Results: No vesicoureteric reflux occurred in postoperative follow‐up. Women whose ureterovaginal fistula treated by open surgery underwent a longer follow‐up time (12‐126 months) than the laparoscopic group (7‐39 months). The successful repair of the ureterovaginal fistula was achieved similarly in the open surgery group (96.67%) and laparoscopic group (95.00%). There was no immediate or delayed complication in the laparoscopic group. No significant difference was found between the laparoscopic repair group and the open surgery group in postoperative complications.

Conclusions: Our study preliminarily indicates that mucosa to mucosa anastomosis ureteroneocystostomy without anti‐reflux technique is feasible, effective and offers durable results without apparent complications, and laparoscopic ureteroneocystostomy with can be performed safely with a success rate compared to that of open surgery but with less morbidity and quick convalescence.

MP08-12 TOT‐TVT results revisited : an overestimated facility and an underestimated complication rate. Report on 280.000 cases in France (period 2009‐2018).

M Devonec

GH Lyon‐Sud, Urology department

Introduction & Objective: To analyze the re‐operation rate, after more than 280.000 cases of TVT and TOT operated in the period 2009 and 2018, as reported in France by surgeons from public hospitals and private clinics.

Methods: The official national records of the ATIH (Technical Agency on Hospitalization Information) and PMSI data (Medicalization Program of health Information Systems) were consulted for the period 2009‐2018.

The number of TVT and TOT reported each year were examined, as well as the number of complications reported each year for these two operations. Before 2012, the same code JDDB001 was used for TVT or TOT. After 2012, a different code was used for TVT JDDB007 and for TOT JDDB005. Six types of re‐operations were reported and analyzed :tape section vaginal route JRPA0010, tape ablation vaginal route JRGA0010, tape partial ablation laparotomy route JRGA0020, tape total ablation vaginal and laparotomy routes JRGA0030, tape total ablation vaginal and laparoscopy routes, tape partial ablation laparoscopy route JRGC0010. It was not possible to distinguish separately the complications related respectively to TVT or to TOT. The delay before re‐operation was also studied.

Results: Over the 10 years of the study a total number of 281.166 cases of TVT or TOT were performed . The number of TVT or TOT per year decreased slightly from 32.845 cases in 2009 to 28.166 in 2018. The number of re‐operations was remarkably stable, and varied from 2.300 in 2009 to 2.394 cases in 2018. The percentage of re‐operations each year was 8.4 % of the TVT or TOT operated each year. The most frequent re‐operations were tape ablation vaginal route 54% and tape section vaginal route 33% of the re‐operations performed each year. The longitudinal analysis of the delay before re‐operation showed 44% of the re‐operations were performed during the first year after tape implantation, 76% during the first 3 years and 84 % during the 4 first 4 years. After 4 years the number of re‐operations was low but still kept going.

Conclusions: TOT or TVT have the reputation of a simple operation, « an intern operation ». However, there is a discrepancy between surgeons opinion of facility and facts : an elevated rate of re‐operations, without considering medical complications (pain, hyperactive bladder …) the immersed part of the iceberg. Whose responsibility ? Surgeon competence probably not ; tape material, TVT ‐TOT technique possibly both. There is a need to reconsider the relevance of the prefered use of the former and to look for other material and technique. Autologous material, readjustability, totally removable material if needed should be the next objective.

MP08-13 Buccal, Boari, or Autotransplant over Bowel: Management of Proximal to Mid Ureteral Strictures

K Radadia, AK Chow, KG Sands, S Ogawa, B Patel, K Du, E Kim, RS Figenshau, G Murphy

Washington University School of Medicine

Introduction & Objective: Advances in surgical technique have changed management of proximal to mid ureteral strictures (PMUS). We evaluate our institutional experience with these strictures.

Methods: A retrospective review was performed from 3/2018‐10/2019 on management of patients with PMUS by a single surgeon. Robotic ventral onlay buccal ureteroplasty with omental wrapping (RBU), ureteral reimplant with psoas hitch and boari flap (Boari), or renal autotransplant (RA) were performed depending on stricture etiology, length, location, and health of ureteral plate. Patients had a ureteral stent for six weeks and followed for recurrence with a renal Lasix scan at three months and ultrasound at one year. Post‐operative complications, voiding symptoms (LUTS), and stricture recurrence were recorded.

Results: Fourteen patients had PMUS with a mean age of 52.1 years and stricture length of 5.0 cm (Table 1). Robotic buccal ureteroplasty was performed in seven proximal and two mid ureteral strictures. A ureteral stent was placed preoperatively to ensure a reasonable ureteral plate and a healthy distal ureter. A boari flap was performed open on four patients with concomitant operations by hernia or colorectal surgeons. Renal autotransplant was performed on one patient with a prior gun shot injury to the ureter causing a 4 cm proximal obliterated segment. No patients have recurred to date with 12.9 months mean follow up. Two patients undergoing RBU and one Boari developed urinary tract infections and one Boari patient had a small bowel obstruction that resolved with conservative management. LUTS were more common in Boari patients than RBU (Table 2).

Conclusions: Robotic ventral onlay buccal ureteroplasty with omental wrapping is an excellent technique for PMUS with a low recurrence rate in our series with 12.9 months of mean follow up. Ureteral stents prior to RBU ensured a wider plate to graft. We prefer this technique to Boari if possible due to lower rates of LUTS. Our algorithm (Figure 1) favors RBU, RA or Boari over ileal interposition if possible due to lower complication rates.

MP08-14 1‐year Outcome After Bilateral Uterosacral Ligament Replacement ‐ Comparison of Abdominal and Laparoscopic Surgical Techniques in Treatment of Pelvic Organ Prolapse and Urinary Incontinence

S Ludwig, F Thangarajah, C Eichler, B Morgenstern, P Mallmann

University of Cologne, Dept. of Obstetrics and Gynecology, Div. of Pelvic Floor Reconstructive Surgery

Introduction: Laxity of the anterior vaginal wall leads to the funnelling of the bladder neck and triggering inappropriate micturition reflexes and thus might lead to urinary incontinence. In the upright body position the anatomical support of the anterior vaginal wall (on which urethra and bladder base rest) is mainly ensured by the cervix / uterus, thus an intact apical suspension is mandatory. Sacrocolpopexy (SCP) is the gold‐standard for apical reconstruction. The technical performance of each SCP varies according to the surgeon's discretion, and comparison of clinical outcomes may be hampered. Therefore, a comprehensible surgical technique for bilateral apical fixation with a minimum amount of synthetic material was developed. Therefore, a comprehensible surgical technique for bilateral apical fixation with a minimum amount of synthetic material was developed.

Objective: Evaluation of the clinical 1‐year results after cervicosacropexy (either abdominal or laparoscopic) and its effect on prolapse and urinary incontinence.

Methods: Retrospective analysis in a tertiary center of women with POP‐Q stages I‐IV and urinary incontinence. All patients received a standardized bilateral uterosacral ligament (USL) replacement using polyvinylidene‐fluoride tapes (PVDF) either open abdominal (cervicosacropexy, CESA) or laparoscopic (laCESA). These PVDF tapes were identical in shape, that is 0.4cm width and 8.8cm length. Clinical outcome was assessed at 12 months.

Results: 145 patients were evaluable, 75 patients were operated with the abdominal, 70 patients with the laparoscopic approach. No major complications occurred intraoperatively and no mesh erosions were detected within 1‐year postoperatively. There was no significant difference in clinical outcome one year after surgeries. Apical support (POP‐Q stage 0) was restored in 100% of patients and urinary continence restored in 59% of patients (59% after laparotomy vs 62% after laparoscopy, respectively). After laCESA, patients stayed 3 days in mean compared to 5 days after CESA. Regarding the operating time, a CESA lasted in mean 120 minutes (89 ‐ 168 minutes), whereas a laCESA lasted in mean 89 minutes (58 ‐ 128 minutes).

Conclusions: In contrast to many other apical fixations, both USL were replaced using a clearly defined surgical technique (in term of type of material, size, shape of mesh, and positioning). This standardization ensured comparable and reproducible clinical outcomes, despite different surgical access paths.

MP08-15 Ureteral injuries: long term results of endoscopic ureteral realignment

H Johnson, S Parsons, P Mezes, G Collin, N Collin, J Philip

Bristol Urological Institute

Introduction & Objective: Ureteral injuries can occur in complex pelvic surgeries or trauma. Endoscopic ureteric re‐alignment (EUR); either with antegrade or rendezvous approach for ureteric injury obviates the need for open or minimally invasive complex surgery. Long term results of endoscopic management for ureteric injuries are described with technical modifications to enable increased success.

Methods: Over an eight‐year period, patients who were referred with ureteric injury were included. These patients had had pelvic surgery (open or minimally invasive), with an interval CT scan identifying ureteric injury post‐surgery. Management was a four‐tiered approach with nephrostomy decompression, antegrade pyelogram, antegrade stenting, rendezvous realignment with tandem or covered stents.

Results: 57 patients with a mean age of 65 years underwent ureteric re‐alignment with the majority of patients having mid‐/ lower ureteric injuries. Half of these patients needed rendezvous re‐alignment. 91% of the patients had successful realignment with 58% stent‐free at follow‐up (mean 2.5 years). Obstetric and Gynaecologic injuries accounted for the majority of non‐urological causes, with 33% of patients being stent‐free. Urological diseases associated injuries were often stent dependant.

Conclusions: Endoscopic ureteral realignment has a high (91%) success rate especially in patients with ‘clean’ injuries. This can be attributed to modifying rendezvous realignment technique, such as enabling multi‐planar endoscopic evaluation to minimise retroperitoneal defect, balloon dilatation of strictures, tandem stents; and use of Allium^® stents in patients with a longer ureteric defect. It enables avoidance of complex re‐implantation surgery. Patients should be counselled regarding the period of stenting & possible further endoscopic surgery.

MP08-16 Differences in Surgical Treatment of De Novo Urge Incontinence Occurring Post‐Holmium Laser Enucleation of the Prostate

L Richards, BB Whiles, D Mazzotti, K Thurmon

University of Kansas Medical Center

Introduction & Objective: Holmium laser enucleation of the prostate (HoLEP) is an effective option for patients with lower urinary tract symptoms secondary to benign prostate hyperplasia. Although HoLEP has well‐established and durable outcomes, it carries a risk of iatrogenic urinary incontinence. Most patients with de novo urge incontinence (UI) experience transient symptoms with resolution rather quickly, but some patients have persistent incontinence. Due to its relative rarity, patient factors that increase the risk of post‐HoLEP persistent UI requiring surgical treatment have not been examined. In this study, we identify management options for persistent UI after HoLEP and examine patient risk factors for the condition. Furthermore, we examine symptom response to three surgical treatment options for de novo UI post‐HoLEP.

Methods: A retrospective study was performed to identify patients who underwent HoLEP at a single institution between 2016 and 2019. Patient demographics including age, BMI, race, smoking status, history of previous procedures, diabetes, erectile dysfunction, UTI, and pelvic floor physical therapy were evaluated. Prescriptions for alpha blockers, 5‐alpha reductase inhibitors, anticholinergic agents, and beta‐3 agonists were also identified. Bidirectional stepwise regression was performed using the history of a surgical treatment for UI as the outcome. These procedures include intravesical onabotulinumtoxinA (Botox) injection, peripheral tibial nerve stimulation (PTNS), or sacral neuromodulation (SNM). AUA symptom and quality of life scores were compared in patients with persistent UI that progressed to surgical treatment to those that did not.

Results: A total of 340 patients underwent HoLEP during the study period. We evaluated 28 possible risk factors for persistent UI requiring surgical management. Eight (2.4%) patients received one of the third line therapies, with 1 receiving PTNS, 6 receiving SNM alone, and 1 receiving both SNM and Botox. Our current model suggests that a history of UTI prior to HoLEP procedure increases the odds of developing the UI outcome by 36.98‐fold; 95% CI [2.75, 496.90]; p = 0.006.

Conclusions: Although persistent UI after HoLEP is rare, its management and associated risk factors are important to understand. Prior UTI is associated with increased risk of post‐HoLEP UI. These are preliminary results and future study will further investigate risk factors for persistent UI post HoLEP as well as compare outcomes for management options.

MP08-17 Application of bladder muscle flap in upper and/or middle ureteral stricture（9 cases）

Y Yuan, z Zhang, W Yuting, L Folin, Z Guoxi, X Zou

Introduction & Objective: To explore the clinical effect of bladder muscle flap in the treatment of middle and upper ureteral stricture.

Methods: 9 patients with upper and/or middle ureteral stenosis were treated with bladder muscle flap from February 2018 to December 2019, including 7 cases of ureteral calculi lithotripsy and 2 cases of ureteral injury secondary to gynecological surgery. There were 2 males and 7 females with an average age of 48 years (range, 26‐69 years). There were 5 cases on the left side and 4 cases on the right side. Laparoscopic ureteroplasty with bladder muscle flap and ureteroplasty with open bladder muscle flap were performed in 4 cases and 5 cases respectively. 7F ureteral stent was placed in the ureter. The length of bladder muscle flap ureter was 17‐25 cm, with an average of 20.4

Results: Operations were successful in all of the 9 cases, no conversion to open surgery in laparoscopic surgery. The operation time was 90‐180 min (mean 125 min). Intraoperative blood loss was estimated to be 50‐200 ml, with an average of 100 ml. The drainage tube was removed 2‐5 days after operation, with an average of 4 days. The average postoperative hospital stay was 9 days. The catheter was removed 2 weeks after operation, and the serum creatinine and urea nitrogen were normal. The ureteral stent was removed 2 months after operation. At 3months after operation, IVU or CTU showed that the ureter was unobstructed, no stenosis was found, and hydronephrosis was remissive. All the cases were followed up for 6 to 18 months, no ureteral stricture and hydronephrosis aggravation were found.

Conclusions: Ureteroplasty with bladder muscle flap in the treatment of middle and/or upper ureteral stricture is safe and effective, which is worthy of clinical application.

MP08-18 Artificial Urinary Sphincter Is Better than Slings for Moderate Male Stress Urinary Incontinence with Acceptable Complication Events: A Systematic Review and Meta‐analysis

L Lin, L Zhou, H Li, K Wang

Introduction & Objective: This meta‐analysis aimed to compare the efficacy of artificial urinary sphincter (AUS) and slings for the treatment of moderate male stress urinary incontinence (SUI) based on existing data.

Methods: The study was in accordance with the Preferred Reporting Items for Systematic Reviews and Meta‐Analysis. We searched the widely acknowledged database including PubMed, Embase (Ovid version), Medline (Ovid version) and Cochrane Central Register of Controlled Trials (till August 2020). Male patients with moderate SUI who underwent AUS or slings procedure over 18 years old and had been monitored with mean follow‐up time of at least 12 months were included. The primary outcome were success events defined as daily pad use with 0‐1 pad/d post‐operatively. Articles with similar outcome were considered suitable for inclusion. Secondary outcome included complication events of infection, erosion, acute urinary retention and surgical revision.

Results: Five studies with a total of 509 patients (295 for slings and 214 for AUS) were recruited. Success events were higher in AUS with odds ratio (OR) = 0.57 (95% confidence intervals (CIs): 0.36‐0.90). As for complication events, no significant difference was discovered between slings and AUS groups (OR = 1.04, 95% CIs: 0.61‐1.77, P = 0.88).

Conclusions: To conclude, AUS was better than slings for moderate male SUI treatment according to daily pad use with acceptable complication events. Slings also had clinical value and were options when patients refused inserted mechanical devices. More higher‐quality evidences are needed to confirm the efficacy of AUS and slings in moderate male SUI.

MP08-19 Robotic buccal ureteroplasty: early single institutional outcomes

MS Tonzi, B Waldorf, J Lange

University of Tennessee College of Medicine at Chattanooga

Introduction & Objective: Ureteral stricture disease, especially in the proximal and mid ureter, is a challenging surgical problem. Traditional approaches, such as ileal ureter interposition or renal auto‐transplantation, have significant associated morbidity. Robotic buccal mucosal graft (BMG) ureteroplasty is an alternative technique for managing complex ureteral stricture disease. We present early outcomes for six patients who underwent robotic BMG ureteroplasty at our regional tertiary care center.

Methods: Six patients underwent robotic BMG ureteroplasty for benign ureteral stricture disease between January 2019 and February 2021 at our institution. The decision to proceed with robotic BMG ureteroplasty was made by the primary surgeon at the time of the operation based on preoperative imaging analysis, patient characteristics, and intraoperative findings. Patient demographics, perioperative data, and short‐term results were analyzed retrospectively. The primary outcome was successful repair of the ureteral stricture, defined as resolution of flank pain on the affected side, without need for secondary intervention.

Results: All strictures were secondary to iatrogenic injury or recurrent nephrolithiasis, except for one resulting from a failed robotic pyeloplasty. All six patients underwent technically successful robotic BMG ureteroplasty by a single surgeon. There were no significant intraoperative complications. Mean OR time was 280 min (Range 146‐375 min), mean EBL was 25 ml (range 0‐50 ml), and each patient was discharged home on post‐operative day 1. Mean stricture length was 3.3 cm (range 2.5‐4cm). 5 of 6 strictures were located in the proximal ureter, while 1 stricture was located in the distal ureter. Follow up data was available in 4 of 6 patients. Average follow up time was 10 months. Each patient demonstrated clinical success defined as resolution of flank pain in the affected kidney. To date, no patient has developed stricture recurrence, and no patient has required secondary intervention. There were no complications involving buccal harvest sites.

Conclusions: Early results indicate that robotic BMG ureteroplasty is a safe and effective option for the management of complex ureteral stricture disease. However, longer term data on patient outcomes is necessary for a full assessment of this technique. With adequate surgeon experience, robotic BMG ureteroplasty can be performed safely and effectively.

MP08-20 Robotic assisted Vesico‐vaginal fistula repair: Our technique and outcomes

R Batra, A Singh, A Ganpule, R Sabnis, M Desai

Muljibhai Patel Urological Hospital, Nadiad

Introduction & Objective: Vesico‐vaginal fistula (VVF) is an abnormal communication between the bladder and the vagina. Correct diagnosis and prudent timing of repair are essential for successful management of these cases. The clinical scenario is different in all the patients. Most common causes of vesico‐vaginal fistula are abdominal hysterectomy, cesarean sections, malignancy and radiation related VVF, obstructed labour. Robotic assisted VVF repair has shown to be safe and feasible in many studies. Here, we show our technique of robotic assisted VVF repair and our outcomes of last 10 years.

Methods: Retrospective analysis was done for all the cases of Robotic assisted VVF repair done at our institute Muljibhai Patel Urological Hospital, Nadiad, India. Variables analysed were age, cause, location of VVF, size of defect, operative time, catheterisation and post‐operative complications and long term outcomes.

Results: 24 robotic assisted VVF repairs were done in last 10 years. The mean age of patients was 41.37 ± 7.1 years. Mean duration from insult to operation was 7.19 months. The mean size of the defect was 1.5 ± 1.1 cm. Mean duration of catheterisation was 17 ± 3.3 days, and mean duration of drain was 3.7 ± 1.2 days. There were 4 complications. 3 patients required prolonged catheterisation while 1 patient required repeat repair. Location of fistula was supratrigonal in 19 cases. Most common cause of VVF was abdominal hysterectomy (12 cases) followed by laparoscopic hysterectomy (4 cases) follows by caesarean section (2 cases) and malignancy and radiation related fistula ( 2 cases).

Conclusions: Robotic assisted VVF repair is safe, feasible and has excellent success rates. Technical modification with horizontal cystotomy had good results in all the patients.

MP08-21 Clinical outcomes of endoureterotomy on ureteral strictures which lasts after resolution of extrinsic benign causative disease

J Kim, S Bang, K Ko, J Chung, W Song, M Kang, H Sung, M Baek, S Jeon, K Lee, D Han

Department of Urology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea.

Introduction & Objective: Endoureterotomy is generally accepted as the first choice for treatment of ureter stricture. But the success rate can vary depending on the patient selection. Both endometriosis(EM) and retroperitoneal fibrosis(RPF) are typical benign disease that cause extrinsic ureteral strictures. And in both of them, there are effective medical therapeutic agents that can reduce the size of extrinsic causative disease. In many cases, ureter stricture persist even after medical treatment has eliminated extrinsic lesion on imaging. But, there are few data of endoureterotomy in this situation. We assessed the outcome of endoureterotomy on ureteral strictures which lasts after resolution of extrinsic benign causative disease.

Methods: Frome 2011 to 2020, we retrospectively reviewed medical records of patients who treated with medication for EM or RPF, and who underwent endoureterotomy for persistent ureteral stricture after complete resolution of periureteral lesion on imaging. Patient who had underwent open or laparoscopic surgery for ureter were excluded. Surgical outcomes were assessed at 3months, 6months after treatment. Success was defined as improvement of radiologic findings and improved excretion on diuretic renal scan.

Results: Total 19 ureter units (17 patients) were evaluated including 8 cases of EM and 11 cases of RPF. All of them were followed at 3 months and 17 ureter units (16 patients) were followed at 6 months. The overall success rate at 3 and 6 months were 94.7%(18 of 19 cases), 94.4%(16 of 17 cases). In EM group, the success rate at 3 and 6 months were 100% (8 of 8 cases). In RFP group, the success rate at 3 and 6 months were 90.9%(10 of 11 cases) and 88.9%(8 of 9 cases). The failed case underwent no further treatment because of severely decreased renal function.

Conclusions: In this study, the success rate of endoureterotomy after successful medical treatment for the causative extrinsic ureteral disease was dramatically high. In case of ureteral stricture combined with extrinsic diseases such as EM and RPF, sufficient medical treatment should be preceded by surgical intervention. In addition, endoureterotomy should be considered as the first treatment option rather than conservative management or reconstructive surgery in persistent ureter strictures with resolved EM or RPF.

MP08-22 Treatment of mild to moderate stress urinary incontinence using the stromal‐vascular fraction of autologous adipose tissue

AO Papoyan, C Maксимовa, R Safiullin, V Pavlov, R Kazikhinurov

Bashkir State Medical University

Introduction & Objective: Stress urinary incontinence (SUI) after radical prostatectomy is a major problem that affects 9‐16% of patients. Post‐prostatectomy incontinence results from surgical damage to the urethral sphincter as well as to surrounding nerves and supportive tissue. Treatment of urinary incontinence can be conservative including drug therapy, behavioral therapy, physiotherapy, pelvic floor exercises, surgical including sling operations, or periurethral injection therapy with bulking agents. Whereas more invasive approaches like sling operations are more effective but have higher morbidity, while the injection of allogeneic bulking agents is minimally invasive but has poor long‐term efficacy. Various studies have shown the effectiveness of the autologous stromal‐vascular fraction (SVF) as a bulking agent and for the regeneration of local tissues.

Methods: Here we report our experience of SVF transplantation into the periurethral region as a method of stress urinary incontinence treatment. Patients with symptoms of stress urinary incontinence (grade 1‐2) after radical prostatectomy of prostate were treated by injections of SVF into the bladder sphincter. The first stage is lipoaspiration. After this, the stromal‐vascular fraction is separated using special double syringes and centrifugation. After excretion of SVF, transurethral introduction to the zone of the external sphincter of the bladder is performed. Part of the SVF is sent to the BSMU Cell Culture Laboratory for study of the cellular composition using flow cytofluorimetry. Analysis of the SVF obtained from autologous adipose tissue by flow cytometry revealed the expression of markers of mesenchymal stem cells CD44, CD73, CD90. Successful differentiation of the obtained cells into bone, muscle, cartilage tissue demonstrates the presence of multipotent mesenchymal stem cells.

Results: Our study showed that injection of the SVF into the bladder sphincter area is a safe treatment option for SUI. The effectiveness of the method was 58% according to the results of the Pad test, ISIQ‐SF and QoL, complex urodynamic research, uroflowmetry. In the group with a positive effect, the Pad test value decreased on average from 2‐3 to 0‐1, the score on the ISIQ‐SF questionnaire from 7‐11 to 1‐3 and the QoL test from 4‐6 to 1‐2. There were no side effects.

Conclusions: Laboratory diagnostic methods prove the presence of multipotent mesenchymal stem cells and their ability to differentiate. The use of stromal‐vascular fraction in the treatment of mild to moderate stress urinary incontinence in men is an effective and safe method.

MP10-01 Prostatic Urethral Lift real‐world experience is consistent with controlled trial results in both non‐retention and retention subjects

NJ Barber, KL Ng, SN Gange, G Eure, M Rochester

Frimley Park Hospital

Introduction & Objective: Real world studies reflective of heterogenous populations should serve as a litmus test for new technologies, including those within the minimally invasive field for BPH. In order to determine how the UroLift System performs in the real‐world setting compared to previous experience in controlled settings, an analysis was conducted on the large, actively enrolling Real World Retrospective (RWR) study in comparison to the L.I.F.T. pivotal and P.U.L.S.A.R. urinary retention Prostatic Urethral Lift (PUL) trials.

Methods: The Real‐World Retrospective (RWR) study gathered data from 2491 subjects across 22 USA, UK, and Australian sites who had undergone PUL after market clearance. RWR data was then filtered into non‐retention (RWR Group A, n = 2117) and retention (RWR Group B, n = 374) groups. Controlled studies used for comparison were L.I.F.T. ‐ the randomized controlled trial for PUL following non‐retention subjects over 5 years (n = 140), and P.U.L.S.A.R. ‐ a controlled study following retention subjects post‐PUL for 12 months (n = 52). Absolute IPSS scores across all studies were compared at 1, 3, 6, and 12 months post‐procedure using a one‐way ANOVA. Adverse events and catheterization rates of RWR subjects were calculated and compared to L.I.F.T. and P.U.L.S.A.R. studies.

Results: We report similar absolute IPSS scores among all groups at all timepoints following PUL (Figure 1), demonstrating no differences in symptom outcome after treatment between real‐world and controlled studies. Analyses also revealed equivalent safety profiles when comparing real‐world groups with their respective controlled studies. Adverse events in both RWR Groups (A: non‐retention; B: retention) were mild‐moderate, transient, and not elevated compared to L.I.F.T. or P.U.L.S.A.R. 84% of RWR Group A subjects were catheter‐free post‐procedure (excluding catheter placement for standard of care), which is slightly better than the 68% catheter‐free rate of the L.I.F.T. trial. Catheter‐independence of RWR Group B subjects was consistent with P.U.L.S.A.R. results at 1 month (p = 0.2) and at longest available follow up (p = 0.3).

Conclusions: Analysis of PUL real world study results vs. controlled trials demonstrate consistent symptom response, safety, and patient experience, revealing positive and novel findings for minimally invasive therapy in the BPH space.

MP10-02 Real‐World and Controlled Trial Predictors of Durability after Prostatic Urethral Lift (PUL)

NJ Barber

Frimley Park Hospital

Introduction & Objective: Durability is an important component in any BPH treatment, and should be studied in minimally invasive therapies. The LIFT pivotal controlled study demonstrates PUL durability to 5 years, and data in the real‐world have revealed successful outcomes in various BPH populations. Here, we sought to understand how baseline characteristics correspond to PUL durability in the real world and in a controlled setting.

Methods: Uni‐ and multivariate predictive assessments were calculated for the likelihood of a successful response for 2714 non‐retention subjects from the Real‐World Retrospective (RWR) database, i.e. lack of subsequent BPH surgery through the point at which 90% of the population was censored or follow‐up data were no longer available. The analysis included baseline variables such as age, comorbidities, medical history and BPH disease severity (e.g. IPSS, QoL, Qmax). Univariate predictive assessments were performed for subjects from the LIFT trial (LIFT, n = 140). A stepwise procedure was used to select predictors for the multivariate logistic regression models. An odds ratio >1 indicated a higher probability of retreatment.

Results: The variables of age at baseline, duration of LUTS prior to PUL, and comorbidities such as diabetes and obstructive median lobe did not influence PUL durability. Higher IPSS and QoL at baseline significantly predicted an increased likelihood of surgical retreatment for RWR and LIFT patients. Large prostate volume ( >100cc, not applicable to the LIFT study) was not a predictor compared to <100cc prostates. Lower Qmax was a predictor in the LIFT group, but not in RWR. Odds ratios for all significant RWR predictors were close to 1, and the largest significant odds ratio for LIFT was 3.4 with the QoL baseline variable. When QoL was entered into a multivariate model, no other covariates added significantly to the prediction. The RWR analysis included 1070 days of follow‐up based on the density of available data; 154 patients were retreated during this time.

Conclusions: This analysis of baseline variables in the real world and controlled LIFT trial reveals worsened IPSS and QoL as possible predictors of reintervention following PUL, suggesting that a more severe disease state at baseline may increase the likelihood of undergoing subsequent BPH surgery. Urologists may utilize these findings as support to consider BPH interventions earlier in the disease process.

MP10-03 Continuous mode bipolar plasma vaporization of the prostate – Still a “go” after 6 years of follow‐up?

BF Geavlete, C Moldoveanu, C Ene, C Bulai, A Ene, PA Geavlete

“Saint John” Emergency Clinical Hospital, Department of Urology

Introduction & Objective: A prospective, long term, randomized‐controlled study evaluated the efficiency and safety of an energy source enabling a continuous bipolar plasma vaporization of the prostate (C‐BPVP) to be achieved by comparison to the first generation standard bipolar vaporization (S‐BPVP) as well as to conventional monopolar transurethral resection of the prostate (TURP) in medium size benign prostatic obstruction (BPO) cases.

Methods: A total of 180 BPO patients with prostate volume between 30 and 80 mL, maximum flow rate (Q_max) below 10 mL/s and International Prostate Symptom Score (IPSS) over 19 were equally randomized for C‐BPVP, S‐BPVP and classical TURP. All cases were evaluated preoperatively and every 12 months' for a total period of 6 years after surgery by IPSS, Q_max, quality of life score (QoL) and post‐voiding residual urinary volume (PVR).

Results: The mean operation time was significantly shorter in C‐BPVP cases by comparison to conventional plasma‐button vaporization and to monopolar resection (31.5 versus 40.6 and 49.8 minutes). Consequently, a substantial 22.4% and respectively 39.1% difference in surgical length was emphasized in favor of C‐BPVP when compared to S‐BPVP and TURP. Significantly lower capsular perforation (1.7% and 1.7% versus 8.3%), and intraoperative bleeding (1.7% and 3.3% versus 11.7%) rates as well as mean hemoglobin drops (0.4 and 0.6 versus 1.4 g/dL) were emphasized in the C‐BPVP and S‐BPVP series when compared to TURP. Also, significantly reduced mean catheterization periods (24.1 and 23.8 versus 73.6 hours) and hospital stays (2.1 and 2.2 versus 4.5 days) were described for the C‐BPVP and S‐BPVP groups. The rate of re‐catheterization imposed by acute urinary retention (1.7% and 1.7% versus 6.7%) was significantly higher among the monopolar resection cases. During all the yearly periodical check‐ups up to 6 years after the initial intervention, statistically superior IPSS and Q_max measurements were determined in the 2 bipolar vaporization study arms.

Conclusions: The new technical improvement of the BPVP procedure was able to reduce the surgical time by an average proportion of 20%. The bipolar plasma vaporization approach emphasized significantly superior perioperative safety features and improved follow‐up voiding and symptom scores' parameters over the standard monopolar resection during the 6 years' long term follow‐up.

MP10-04 Outcome of TransUrethral Enucleation with Bipolar(TUEB) in patients with huge prostate hyperplasia : comparison of prostate volume more than 80ml with less

Y Endo, H Shimizu, J Akatsuka, Y Kondo

Nippon Medical School

Introduction & Objective: Transurethral resection of the prostate has been the standard surgical treatment for benign prostatic hyperplasia (BPH). We reported that the efficacy and safety of TransUrethral Enucleation with Bipolar (TUEB) is comparable to those of TURP for managing BPH. Despite the remarkable progress in minimally invasive treatment, rescent guidelines still recommend open surgery for the treatment of patients with large prostate of more than 80ml. The aim of the present study was to investigate the impact of preoperative prostate volume on the outcome of TUEB. We analyzed the difference of the efficacy and safety of TUEB between patient with PV of more then 80ml and less.

Methods: A total of 180 patients with medication resistant BPH who underwent TUEB in our institution by single surgeon from 2008 to 2015 were retrospectively examined. All patients were evaluated with the international prostate symptom score (IPSS), quality of life score (QoLs), uroflowmetry (Qmax), serum prostate specific antigen (PSA), and transrectal ultrasonography (TRUS) of the prostate. Patients were divided into two groups based on whether their preoperative prostate volume (PV) was greater than 100ml measured by TRUS (PV> = 80ml : huge group (HG), PV <80 : standarad group (SG) ). Perioperative change of IPSS, QoLs, Qmax and PSA were assessed as efficacy. Perioperative serum sodium and hemoglobin decrease and all adverse events were assessed as safety. Chi‐square test and student t‐test was performed to compare outcomes of two groups.

Results: All patients were performed collected with sufficient data performed TUEB. As preoperative baseline value, mean IPSS was 20.4, QOLs 5.0, Qmax 6.6 (mL/s), PSA 6.9 (ng/dL). Postoperatively all of those were improved with statistically significance, mean IPSS was 4.9, QoLs was 1.1, Qmax was 18.9(mL/s), PSA was 1.1 (ng/mL). Mean PSA level decreased 89.8 ± 1.2％ after TUEB. There was neither hyposodemia nor blood transfusion around operation. There were 48 patients (27%) in the HG and 132 (73%) in the SG. Mean PV of each group was 106.2ml ±26.6 (HG) and 52.9ml ±13.7 (SG). Mean operative time of HG (146.2min ±34.0) is significantly longer than SG (85.9min ±22.9). On efficacy decrease of IPSS voiding score on SG is significantly larger than HG, improvement of Qmax on HG is significantly smaller than LG. On safety parameters and AE were comparable.

Conclusions: The efficacy and safety of this novel procedure seem very promising. TUEB also showed sufficient efficacy and safety for the patient with huge PV of more than 80ml. TUEB could be a new gold standard procedure for BPH regardless of PV. Longer follow‐up and larger prospective studies are necessary to confirm these promising results.

MP10-05 Single Surgeon Experience with Procept Aquabeam Aquablation of Prostate: First 55 Cases (with 18‐month Follow‐up)

A Kasraeian, M Alcantara, K Mola Alcantara, A Kasraeian

Kasraeian Urology

Introduction & Objective: Procept Aquabeam Aquablation is a novel, minimally invasive technology for management of BPH, regardless of prostate size or shape. The Aquabeam system is an innovative combination of robotic technology, multi‐dimensional real‐time imaging, and (&) heat‐free waterjet to precisely & accurately remove obstructive prostate tissue in men with BPH. We report our initial experience with our first 55 cases.

Methods: Between July 2018 & May 2019, data was prospectively collected on 55 men who underwent Aquablation of the prostate. Evaluation of LUTS included cystoscopy, urodynamics (UDS), & transrectal ultrasound (TRUS) to measure prostate volume. Pre‐operative (op), intra‐op & post‐op outcomes were prospectively collected & reported.

Results: Pre‐op demographics include mean age of 67 (50 to 84) & mean prostate volume of 100 cc (27 to 252). Of our 55 patients, 39 had prostates larger than 80cc (71%), 24 greater than 100cc (44%) & five (9%) greater than 150 cc. An obstructing median lobe was noted in 47 (85%) of the 55 men. Pre‐op UDS demonstrated severe bladder outlet obstruction (BOO) in 51 of the 55 men (93%). Detrusor instability was noted in 31 men (56%), & 27 of the 55 (49%) suffered from urinary retention with 17 (31%) requiring catheterization prior to procedure. Mean op time was 58 minutes (25‐108). Thirty‐five of the 55 men were discharged on post‐op day (POD) 1, with 13 discharged on POD 2 & three on POD 3. Two patients received transfusions, but in association with pre‐op anemia and hematuria associated with their enlarged prostate. One of two had also received transfusions pre‐operatively. Mean pre‐op hemoglobin (Hgb) was 14 (8.6 to 16.7). Mean immediate post‐op & day of discharge Hgb levels were 13 (9.3 to 16) & 11.8 (7.2 to 15.3), respectively. Of note, 47 of the 55 men reported erectile dysfunction at baseline. Post‐operatively, a 17 point (2‐29) mean decrease in AUA symptom score (AUASS) was noted from 22 (5 to 35), pre‐operatively, to 5 (1‐13), post‐operatively. Post‐op uroflow studies after 4‐6 weeks demonstrated a mean maximum flow rate (Qmax) of 21 ml/s (4.3 to 45), an increase of 13.3 points from 7.4 ml/s (1.9 to 15), pre‐operatively. Erectile function was maintained post‐operatively with a mean SHIM score of 11.5 (range 1 to 25) versus 10.5 (1 to 25), pre‐operatively. All patients completed successful voiding trials post‐operatively, & of those with baseline urinary retention, none currently require any form of catheterization.

Conclusions: The PROCEPT AQUABEAM Aquablation is an innovative technology that offers predictable & reproducible outcomes, independent of prostate size. Aquablation has a short learning curve & is easily reproduced regardless of prostate size or shape

MP10-06 Patients with self reported benign prostate hyperplasia without medical claims data have barriers to healthcare access

CM Forbes, R Hsi, NL Miller

Vanderbilt University Medical Center, Department of Urology

Introduction & Objective: Estimates of the prevalence of benign prostate hyperplasia (BPH) differ by administrative claims data or self‐report based on methodologic differences. We compared patient‐reported BPH diagnoses to administrative claims BPH diagnoses in order to assess prevalence estimates and to assess demographic and socioeconomic factors that influence how BPH is diagnosed.

Methods: We queried the All of Us Research Program, a common dataset of U.S. patients which actively recruits populations which are traditionally underrepresented in biomedical research. We identified adult male participants with and without a history of BPH according to either self‐reported history at enrollment from 2016‐2022, or administrative claims from 1980‐2020. Among 314,277 participants, which included 47% persons from racial minorities, there were 19,384 men over age 50 who had both medical history and medical claims data available. We compared age, race, education, household income, and healthcare affordability and access among patients with a self‐reported history of BPH without medical claims data to those with a claims‐based diagnosis.

Results: The prevalence of BPH was 27% (n = 5259) according to medical claims, and it was 21% (n = 4064) according to self report. Of patients with BPH by either medical claim or self‐reported history (n = 6716), 22% (n = 1457) had a self reported history only. This shows that a significant proportion of patients with BPH did not have a prior BPH‐specific medical claim. Furthermore, patients with only a self‐reported history of BPH were more likely be unable to afford a specialist (p = 0.04) or follow up (p = 0.03), and were more highly educated (p = 0.02) (Table 1).

Conclusions: Determinations of BPH prevalence by claims‐based data alone will not account for 22% of patients according to this national dataset in the US. These patients self‐report a history of BPH without associated medical claims data. These patients are more likely to have barriers to healthcare access. Advocacy and outreach efforts may improve care for this disadvantaged population.

MP10-07 12‐month Outcomes from the Large Real‐World Study and Urodynamic Results from PULSAR Demonstrate PUL is Safe and Effective in Retention Patients

M Rochester, NJ Barber, O Kayes, N Thiruchelvam, K Rajesh, T Page, G Eure, D Grier

Norfolk and Norwich University Hospital

Introduction & Objective: Minimally invasive surgical therapies for BPH should be evaluated in controlled studies and in the real world, and should be tested in various populations of patients including those in urinary retention. Here, we evaluate outcomes of real‐world PUL retention patients and report newly analyzed urodynamics data from the PULSAR retention controlled study.

Methods: The controlled PULSAR study evaluated outcomes after PUL of 52 retention subjects (with ≥1 failed TWOC on alpha blocker at baseline) over 12 months, including SHIM, satisfaction, and urodynamics. The Real‐World Retrospective (RWR) database included PUL subjects across 22 international sites, 512 of which were in active urinary retention status at the time of the PUL procedure. Baseline demographics, absolute symptom response, and AE and catheter‐independence rates were compared between RWR retention (RWR‐r) and PULSAR subjects.

Results: RWR‐r and PULSAR subjects were similar in baseline characteristics of age (71yo for both groups), prostate size (48cc vs. 55cc), and number of implants (4.7 vs. 4.8). Satisfaction was overall high among PULSAR subjects with 90% of PULSAR subjects feeling better, and duration of catheterization before PUL did not differ between most and least satisfied patients (140d vs 114d, correlation p‐value 0.5). Erectile function (SHIM) of PULSAR patients was preserved. 12 PULSAR patients had UDS data available, and at 12 months showed improvements in pdet@Qmax (23%) and BOOI (41%). 5 patients moved out of the obstructed zone (Fig 1); 86% of those who were technically obstructed at 12 months were catheter‐independent, and 83% felt very much better. IPSS, Qmax, and PVR outcomes of RWR‐r subjects were equivalent to PULSAR, and PULSAR QoL was significantly better at 12 months (1.4 vs. 2.1). Catheter‐independence rates were better for RWR‐r vs. PULSAR subjects at 1 month (81% vs. 60%) and at longest available follow‐up (84% vs 73%). Total AE rates were not elevated in RWR‐r subjects vs. PULSAR, and most AEs in both studies were mild‐moderate and transient.

Conclusions: Results from the RWR database were stable and largely consistent with the controlled PULSAR study at 12 months, indicating that PUL is safe and effective in retention patients and may be a viable option for this population of BPH patients.

MP10-08 Interim 2 Year Results for the EVEREST‐I Trial Evaluating the Optilume BPH Catheter System

O Kayes, S Kaplan, M Pichardo, E Rijo Cedano, R Rodriguez‐Lay, G Espino, R Estrella

St James's University Hospital

Introduction & Objective: The Optilume BPH Catheter System is a novel Minimally Invasive Surgical Therapy (MIST) for the treatment of lower urinary tract symptoms (LUTS) secondary to benign prostatic hyperplasia (BPH). The Optilume BPH System utilizes mechanical dilation of the prostatic urethra to achieve an anterior commissurotomy while delivering the drug paclitaxel to maintain urethral patency. The EVEREST‐I study is a prospective, single arm, multicenter study evaluating the Optilume BPH System.

Methods: A total of 80 subjects were enrolled at 6 centers in Panama and the Dominican Republic. Key eligibility criteria included an International Prostate Symptom Score (IPSS) of ≥13, peak urinary flow rate (Qmax) of 5‐15 mL/sec, and prostate volume 20‐80g with no prior MIST or surgical intervention. Medication washouts included 3 weeks for alpha blockers and 6 months for 5 alpha‐reductase inhibitors. Follow up is ongoing, with 54 of 75 expected subjects with 2‐year follow‐up complete. The primary endpoint was responder rate, defined as subjects experiencing a ≥40% improvement in IPSS without receiving additional therapy. Additional outcomes included IPSS, Qmax, and BPH Impact Index. Impact on sexual function was assessed by the International Index of Erectile Function (IIEF) and Male Sexual Health Questionnaire for Ejaculatory Dysfunction (MSHQ‐EjD).

Results: Symptom scores were significantly improved from baseline, with this improvement maintained through the 2‐year follow‐up. The responder rate was 81.8% at 2 years. A single subject received a prostatectomy 18‐months post‐treatment. Qmax improved from 10.9 mL/sec at baseline to 17.7 mL/sec at 2 years (p < 0.001). There was no change in sexual function as measured by the IIEF Overall Satisfaction score or the MSHQ‐EjD Satisfaction/Bother score.

Conclusions: The Optilume BPH System exhibited a significant improvement in both objective and subjective outcomes through 2‐years post treatment. A randomized, controlled trial is ongoing and long‐term follow‐up is planned through 5 years to further define the durability of the results.

MP10-09 Withdrawn

MP10-10 Management of benign prostatic hyperplasia with high tight bladder neck with minimally invasive approach of mini bladder neck distraction and prostatic urethral lift

KL Ng, NJ Barber

Frimley Park Hospital

Introduction & Objective: Optimal urinary flow outcomes from urolift surgery for BPH associated with high and tight bladder necks have been rather challenging. We describe our technique of mini bladder neck distraction with urolift for patients with BPH and concomitant high and tight bladder necks.

Methods: Patients with BPH associated with high and tight bladder necks were diagnosed in our one stop BPH clinic with flexible cystoscopy. They were counselled and consented for the procedure. Surgeries were performed under sedation in day surgery and were discharged on same day. Mini bladder neck distraction was achieved with minimal electrocautery of a shallow depth by incision at 6oclock midline before further urolift implants delivered in 4D fashion to enhance the bladder neck widening.

Results: 36 patients were recruited in our centre from June 2018 – Oct 2020. Median age was 66 (44 ‐ 80), mean preop mean PSA 1.27ng/mL and median prostate volume of 32.5cc. Mean preop Qmax of 11mls/s improved to 25.8mls/s post op and a mean 52% reduction in post void residual volumes. There was a reduction of 13 points in IPSS (66%) with preop mean IPSS 19 to 6.7 post op, with QoL improvement from 4.3 to 1.3. All men who had normal antegrade ejaculation preop reported no deterioration in ejaculation post operatively.

Conclusions: Mini bladder neck distraction with urolift is a safe and effective minimally invasive technique for BPH with high/tight bladder neck with excellent improvement in LUTS and preservation of ejaculatory function.

MP10-11 ThuLEP vs open simple prostatectomy for the treatment of prostates larger than 150 cc

M Maltagliati, L Berti, U Besana, C Buizza, M Sighinolfi, S Micali, BC Rocco, G Bozzini

ASST Valle Olona

Introduction & Objective: Thulium Laser Enucleation of Prostate (ThuLEP) is currently one of the alternatives to open simple prostatectomy (OP) in patients with benign prostatic hyperplasia (BPH) and prostates over 80 cc. However, enucleation of large prostates is believed to be a more challenging and time‐consuming procedure. The aim of our study is to report intraoperative, early and long term postoperative outcomes of ThuLEP and OP in patients with prostates larger than 150 cc.

Methods: We performed a prospective study on 385 patients with chronic and acute urinary obstruction (IPSS >20, Qmax <12) due to BPH and prostates >150 cc. 193 patients (Group A) underwent ThuLEP and 192 patients (Group B) underwent OP. Patients with urethral strictures, bladder stones, acute urinary tract infection, or with a history of prostate surgery were excluded. Ethical committee approval was obtained, and patients signed the informed consent. The Cyber TM 200 (Quanta System, Italy) and the Cyber Blade morcellator (Quanta System, Italy) were used to perform ThuLEP. All patients were evaluated preoperatively and postoperatively. Blood loss, catheterization time, irrigation volume, hospital stay and operative time were compared between the two groups. 3 months after surgery patients were also evaluated using the International Prostate Symptom Score (IPSS), maximum flow rate (Qmax), and postvoid residual urine volume (PVR).

Results: Mean prostate volume was 196.0 cc (150‐350 cc) in the ThuLEP group and 189.0 cc (150‐280 cc) in the OP group. Mean surgical time was 115.5 ± 44.7 minutes for ThuLEP and 98.5 ± 26.2 minutes for OP. Mean removed tissue weight was 149.0 g in group A and 172.7 g in group B. Catheterization time was 1.7 days in group A and 8.5 days in group B. Hospital stay was 2.3 days in group A and 11.9 days in group B. Median haemoglobin decrease was 1.05 g/dl in group A vs 5.43 g/dl in group B. 27 patients in group B (14.06%) vs 3 patients (1.55%) in group A required blood transfusions due to postoperative bleeding. During the 3‐month follow‐up, the procedures did not demonstrate significant differences in terms of Qmax, IPSS and PVR.

Conclusions: Despite similar results after three months from the procedure, simple transvescical prostatectomy is characterized by longer postoperative hospitalization and catheterization time and higher blood loss compared to ThuLEP. ThuLEP is slightly longer to perform, but has proved to be a safer treatment option in patients with prostates over 150 cc.

MP10-12 Evaluation of the learning curve for aquablation therapy of the prostate: a single‐center analysis

K Vogt, B Becker, AJ Gross, C Netsch

Department of Urology, Asklepios Hospital Barmbek, Hamburg, Germany

Introduction & Objective: In aquablation therapy, an automatic ablation is carried out after sonographic measurement of the prostate adenoma. It is postulated that the surgical result depends less on the ability of the surgeon than on the computer‐controlled tissue removal. The aim of our study was to evaluate the individual learning curve of aquablation therapy.

Methods: 45 consecutive patients with benign prostatic hyperplasia (BPH) were treated by a single surgeon (CN) without technical experience. The surgeon completed a cadaver course and was accompanied by a proctor during the first 10 procedures. The learning curve was determined by the change in the surgical time over the patient series. All data is expressed as median (interquartile range).

Results: The median age was 67 (62 ‐ 71) years and prostate volume was 70 (50 ‐ 85) ml. The surgical time was 44 (30 ‐ 55) min. Aquablation has been successfully performed in all patients. IPSS (20. 5 vs. 9) and QoL (5 vs. 2) significantly improved at discharge (p < 0. 001). The catheterization time and the postoperative stay were 2 (2 ‐ 3) days, respectively. Hemoglobin loss was 2 (1. 3 ‐ 2. 9) g/dl. Transfusions were not necessary. Reoperations (bladder tamponade, persistent bleeding) were performed in 3 patients (6. 6 %). A postoperative urinary retention occurred in 4 (8. 8 %) patients and 3 (6. 6 %) patients developed a urinary tract infection. 5 (11. 1 %) patients developed a bladder tamponade that could be evacuated via catheter. The median operation time decreased from 55 (patients 1 ‐ 10) to 30 minutes (patients 31 ‐ 40, p < 0. 001).

Conclusions: Aquablation therapy is a safe surgical procedure and leads to an immediate improvement of the micturition during the learning curve of the procedure. After 30 procedures, a significant reduction in the surgical time has been shown.

MP10-13 Comparison of vaporization and enucleation techniques based on the functional outcomes and complications of patients with benign prostatic hyperplasia: systematic review and meta‐analysis.

A Shpikina, A Morozov, M Taratkin, A Novikov, D Enikeev

Institute for Urology and Reproductive Health, Sechenov University, Moscow, Russia

Introduction & Objective: Nowadays the most commonly used methods of BPH surgical treatment are vaporization (PVP) and enucleation of the prostate (EEP). We aimed to compare intra‐ and perioperative results of the patients who underwent PVP and EEP.

Methods: A systematic literature search was performed in 3 databases (MEDLINE, Web of Science and Scopus) on a search query: (EEP OR «prostate enucleation» OR «BPH enucleation») AND (PVP OR prostate AND vaporization) according to PRISMA guidelines. The detailed search strategy is available at Prospero, CRD42020204739. The scope of the review according to PICO process is as follows:

P ‐ patients with BPH.

I ‐ any types of EEP or PVP

C ‐ preoperative data, operation characteristics, outcomes of different types of EEP and PVP

O ‐ functional outcomes, effectiveness of the procedures, safety.

Primary outcomes were functional results (IPSS, QoL, PVR, Q_max). Secondary outcomes were intraoperative results, postoperative PSA and prostate volume, complications, and recurrence rate.

Results: The search identified 436 articles, and the final sample contained 15 articles covering a period 2011‐2020 years. Functional outcomes (IPSS, QoL и Q_max) were comparable at 12 months follow‐up (Figure 1). Elkoushy et al. showed benefit of EEP over PVP at 36 months follow‐up, IPSS 7.2 ± 8.4 vs 3.1 ± 4.6, p = 0.01, and Qmax 24.3 ± 16.2 ml/s vs 28.1 ± 10.2 ml/s, p = 0.001. While EEP and PVP duration did not differ significantly in BPH <80 cm³, higher BPH volume was associated with longer operative time. Complication rate (Clavien‐Dindo I and II) was higher in the EEP group (13 – 42%) comparing to PVP (10.3 – 21.7%), especially the percentage of blood transfusion and transient urinary incontinence. But the rate of complications grade IIIa and higher was similar (3 – 6%). Reoperation rate was significantly higher in the PVP group at 60 mo. follow‐up, 2.7% vs 0%, p < 0,05. Postoperative prostate volume and PSA level were also higher in the PVP group.

Conclusions: Short‐term outcomes of the patients were comparable in both enucleation and vaporization groups. Long‐term results including the percentage of relapse were better in patients who underwent enucleation of the prostate.

MP10-14 The impact of benign prostatic hyperplasia surgery on erectile function: a systematic review and network meta‐analysis of randomized‐controlled trials

D Jabarkhyl, A Light, O El Hage, P Dasgupta

GKT School of Medical Education, King's college London

Introduction & Objective: Benign prostatic hyperplasia (BPH) is an independent risk factor for erectile dysfunction. Numerous treatment modalities have recently emerged for BPH. These all risk erectile dysfunction yet may also improve function. A systematic review with network meta‐analysis is crucial for identifying how modalities benefit or worsen erectile function, an important patient‐centred outcome.

Methods: In October 2019, MEDLINE, Embase, and Web of Science were searched for randomized‐controlled trials (RCTs) comparing BPH surgical interventions. The primary outcome was post‐operative International Index of Erectile Function‐5 (IIEF‐5) score at 6, 12, 24, and 36 months. Bayesian network meta‐analysis using a random‐effects model was performed with meta‐regression. Baseline IIEF‐5 score was chosen as the covariate. Using monopolar transurethral resection of the prostate as the reference intervention, mean differences (MD) with 95% credible intervals (95% CrI) and rank probabilities (p) were calculated. PROSPERO registration: CRD42019155506.

Results: From 4606 results, 48 RCTs (5156 patients) encompassing 12 techniques were included (Fig.1). Prostatic urethral lift (PUL) ranked highest for IIEF‐5 score at 6 months (11 techniques; p = 0.581; MD 2.4, 95% CrI ‐0.71 to 5.6), 12 months (12 techniques; p = 0.782; MD 2.9, 95% CrI ‐0.26 to 6.1), and 24 months (9 techniques; p = 0.948; MD 3.6, 95% CrI 0.14 to 7.1). At 36 months (6 techniques, not including PUL), bipolar transurethral resection of the prostate ranked highest (p = 0.424; MD 0.25, 95% CrI ‐0.53 to 0.91). Lowest ranking treatments were laparoscopic simple prostatectomy at 6 months (p = 0.360; MD ‐0.65, 95% CrI ‐2.5 to 0.98) and 36 months (p = 0.461; MD ‐0.48, 95% CrI ‐1.8 to 0.77), prostatic arterial embolization at 12 months (p = 0.709; MD ‐3.3, 95% CrI ‐8.3 to 1.9), and Aquablation at 24 months (p = 0.464; MD ‐0.97, 95% CrI ‐3.7 to 1.7).

Conclusions: Based on network meta‐analysis, PUL produces superior erectile function benefit up to 24 months. In contrast, laparoscopic simple prostatectomy produced worse erectile function at 6 and 36 months. PUL data with longer follow‐up is required, plus further RCTs analyzing other new modalities.

MP10-15 New Visual Prostate Symptom Score versus International Prostate Symptom Score in Men with Lower Urinary Tract Symptoms: a prospective comparison

C Laranjo Tinoco, F Diaz Ferreira, A Cardoso, R Matos Rodrigues, S Anacleto, P Passos, E Lima, M Cerqueira Alves, CA Oliveira

Hospital de Braga, EPE

Introduction & Objective: The International Prostate Symptom Score (IPSS) is an important tool in assessing lower urinary tract symptoms (LUTS) in men with benign prostate hyperplasia (BPH). Due to its limitations, alternative scores emerged, like the New Visual Prostate Symptom Score (VPSS). The aim of this study was to compare and correlate both these questionnaires.

Methods: 100 BPH patients with LUTS were prospectively evaluated between August and November 2017. Exclusion criteria included impared cognitive disfunction, marked visual difficulties, recent urethral catheterization (in the previous month), inability to perform uroflowmetry or voided volume <150mL. Patients answered both questionnaires in the presence of the main investigator. Data collected included the patients' age; level of education; IPSS and VPSS filling time, need of investigators' assistance during filling and total scores; uroflowmetry parameters (Qmax and Qavrg); Prostate Specific Antigen (PSA) value; and prostate volume on vesical ultrasonography. Statistical analysis was performed with Spearman correlations and the Wilcoxon test.

Results: Mean age was 68 years (SD = 9.74) and less than 30% of the patients had completed more than 4 years of schooling. 89% of the patients were able to complete the VPSS without help as opposed to 59% in the IPSS (Graph 1). Spearman correlation results showed significant correlation of IPSS total with VPSS total (r = .651, p < .001). Both the IPSS and the VPSS had a negative correlation with Qmax (r = ‐.201, p = .046 and r = ‐.228, p = .023, respectively). More correlation results can be found in Table 1. The median time spent filling the IPSS (175s, IQR = 54) and the VPSS (93.5s, IQR = 50) was significantly different (Z = 8.68, p < .001).

Conclusions: VPSS correlates significantly with IPSS and Qmax. It can be completed without assistance by a greater number of men and it requires a shorter time to fill in. These findings suggest that VPSS can accurately assess presence and severity of LUTS in a wider population than IPSS.

MP10-16 Withdrawn

MP10-17 Withdrawn

MP10-18 SoracteLite^® Transperineal Laser Ablation as Novel Minimal Invasive Treatment for Benign Prostatic Obstruction: Initial Results of a Pilot Study

R van kollenburg, LA van Riel, JR Oddens, TM de Reijke, HP Beerlage, M de Bruin

Department of Urology, Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, the Netherlands

Introduction & Objective: Surgical treatments for lower urinary tract symptoms (LUTS) caused by benign prostatic obstruction (BPO) provide good outcomes, but require transurethral approach and anesthesia. Recent minimal invasive treatments are more patient friendly, but risks such as strictures and hematuria persist due to the transurethral approach. SoracteLite^® transperineal laser ablation (TPLA) is a novel office based technique that can be applied under local anesthesia with optional conscious sedation, by a transperineal approach. In this prospective pilot study, we determine 1) safety and feasibility, 2) possibility of TPLA using local anesthetics and 3) functional outcomes of TPLA for men with LUTS due to BPO.