Efficacy,Safety,and Durability of 532 nm Laser Photovaporization of the Prostate with GreenLight 180 W XPS in Men with Acute Urinary Retention

Abstract

Objective:

We assessed the effectiveness and durability of 532 nm laser photovaporization with GreenLight XPS in men with and without preoperative urinary retention.

Materials and Methods:

From 2010 to 2017 we prospectively studied men who underwent photovaporization of the prostate (PVP) for obstructive lower urinary tract symptoms (LUTS) secondary to BPH. The cohort was retrospectively divided into those with catheter dependent retention and those with elective PVP. Primary endpoints were catheter-free rate and improvement in quality of life (QoL) scores, international prostate symptom score (IPSS), maximum urinary flow rate (Qmax), and postvoid residual (PVR). The secondary endpoints of the study were complication outcomes as defined by the standardized Clavien-Dindo grading system.

Results:

One hundred thirty-seven men with preoperative retention and 195 men without preoperative retention underwent PVP. Men with preoperative retention were older (70 years vs 66 years; p < 0.001), had a higher American Society of Anesthesiology (ASA) score, and had a higher prevalence of neurologic disease (8% vs 2.6%; p = 0.04). These men also had a larger prostate volume (76 cc vs 69 cc; p < 0.001) and higher prostate specific antigen (5 ng/mL vs 2.7 ng/mL; p < 0.001) than those without retention. Patients with preoperative retention also had higher preoperative baseline IPSS and QoL score. After PVP they improved to values similar to those without retention, with durability up to 24 months. After PVP, men in preoperative retention had similar rates to fail their first void trial (18.2% vs 10.3%, p = 0.053). There was a 96% catheter-free rate in the men with preoperative retention. The rate of complication was higher in the nonretention group, specifically at 90 days (35.4% vs 21.2%; p = 0.009), with almost all the complications being Clavien-Dindo grade 2.

Conclusion:

PVP is an effective, safe, and durable treatment for men in acute urinary retention (AUR) with a catheter-free rate of 96%. The improvement is similar to those who did not present in AUR.

Introduction

Acute urinary retention (AUR) is the inability to void, which is often associated with pain, urgency, and lower abdominal discomfort.¹ AUR related to benign prostatic hyperplasia (BPH) is a growing issue. It is estimated that 10% of men in their seventies and nearly one-third of men in their eighties will experience AUR, within 5 years.² Furthermore, Roehrborn and colleagues showed that 11.9%, 5.2%, and 4.2% of patients on alpha-blockers, 5 alpha reductase inhibitor, and combination of both will experience AUR.³

Medical treatment with alpha-blockers represents the initial management of men with AUR. However, transurethral resection of the prostate (TURP) is considered in patients with retention despite ongoing medial therapy.⁴ Thus, surgical treatment is required in this subgroup of patients. TURP represents the gold standard surgical management in patients with urinary retention related to BPH.⁵ According to the National Institute for Health and Care Excellence (NICE) guidelines, there is insufficient evidence to support the adoption of GreenLight photovaporization of the prostate (PVP) in patients with urinary retention.⁶

We sought to determine the efficacy of 532 nm laser photovaporization with GreenLight 180 W XPS in men with preoperative urinary retention.

Materials and Methods

Patient population

After obtaining institutional review board (IRB) approval, we conducted a retrospective study of prospectively collected data of patients treated with GreenLight PVP for BPH using the XPS-180 W system (AMS, Inc., Minnetonka, MN). Surgeries were performed at a tertiary medical center between the years 2011 and 2017. Patients with known prostate cancer or prior radiation therapy were excluded from the analysis (n = 18). In addition, patients treated with the GreenLight HPS 120-W (n = 36) and patients with history of BPH surgery (n = 38) were also excluded. Treatment indications were in accordance with the American and Canadian clinical practice guidelines. Patients were stratified according to treatment indication. Specifically, patients on permanent or intermittent urinary catheterization were identified as the retention group. Conversely, patients who failed medical therapy but without a catheter were coded as the nonretention group.

Surgical technique

All patients underwent a 532 nm laser PVP with GreenLight 180 W XPS as previously described.⁷ Before the procedure all patients underwent an urinalysis and urine culture; if the culture was positive the patient received culture specific antibiotics immediately before the operation. If the urine culture was negative then the patients were given a dose of preoperative antibiotics (cephalosporin or fluoroquinolone) immediately before the operation. The procedure was done under general or spinal anesthesia. In brief, as reported by Valdivieso and colleagues, PVP was performed until a “TURP-like” cavity lined by capsular fibers was obtained.⁷ After the procedure, a two-way 22F silicone Foley catheter was inserted with a 30 cc balloon postoperatively and removed at the surgeon's discretion typically 24 hours after the procedure. After the operation, the patients were seen in follow-up at 3, 6, 12, and 24 months postoperatively.

Covariates

All men in the study underwent the minimum preoperative evaluation recommended by the American Urologic Association (AUA) before undergoing surgical intervention. Preoperative variables included: patients' age, body mass index, comorbidity score stratified according to the American Society of Anesthesiology (ASA), anticoagulation, and antiplatelet use. Prostate volume was measured using a transrectal ultrasonography (TRUS). In addition, operative characteristics were also recorded: operative time (minutes), lasing time (minutes), energy use (kJ), and energy density (kJ/cc).

Endpoints

The primary endpoints of the study were improvements in symptom score (international prostate symptom score [IPSS]) and quality of life (QoL), as well as uroflowmetry parameters (Qmax and postvoid residual [PVR]). In addition, prostate specific antigen (PSA) reduction was also recoded.

The secondary endpoints of the study were the prevalence of intraoperative and postoperative complications. The latter was stratified according to the Clavien-Dindo grading system. Finally, treatment failure was defined as the need for second BPH surgery or the use of chronic indwelling urinary catheter after surgery.

Statistical analysis

Descriptive statistics focused on frequencies and proportions for categorical variables. Means, medians, and interquartile range (IQR) were reported for continuous variables. The Mann–Whitney test and chi-square test were used to compare statistical significance of differences in medians and proportions, respectively. All statistical tests were performed using R software environment for statistical computing and graphics (Vienna, Austria, version 3.0.1). All tests were two sided with a significance level set at p < 0.05.

Results

After exclusion, there were 137 and 195 patients who underwent PVP in the retention and nonretention groups, respectively. Median catheterization preoperatively was 60 days (IQR: 40–90 days). Regarding patients in the retention group, 92% (n = 126) and 8% (n = 11) were on permanent and intermittent catheterization, respectively. Baseline characteristics are summarized in Table 1. Men in the retention group were older (median age at surgery 70 years vs 66 years; p < 0.001), sicker (ASA 3–4: 27% vs 12.8%; p = 0.002), and more likely to be found to have neurologic disease (8% vs 2.6%; p = 0.04), relative to their counterparts. No statistically significant differences were recorded for history of diabetes or anticoagulant use.

Table 1.

Descriptive Characteristics of 322 Patients Treated with XPS GreenLight Stratified According to Preoperative Retention Status

Variables	No retention (n = 195)	Retention (n = 137)	p
Age
Mean (median)	66 (66)	70 (70)	<0.001
IQR	59–71	62–76
Body mass index
<25	58 (29.7)	58 (42.3)	0.02
25–30	94 (48.2)	62 (45.3)
>30	43 (22.1)	17 (12.4)
ASA score
1	65 (33.3)	31 (22.6)	0.002
2	105 (53.8)	69 (50.4)
3–4	25 (12.8)	37 (27)
History of neurologic disease
No	190 (97.4)	126 (92)	0.04
Yes	5 (2.6)	11 (8)
History of diabetes
No	172 (88.2)	112 (81.8)	0.1
Yes	23 (11.8)	25 (18.2)
Anticoagulant use
No	126 (64.6)	87 (63.5)	0.9
Yes	69 (35.4)	50 (36.5)
5-ARI use
No	66 (33.8)	72 (52.6)	<0.001
Yes	129 (66.2)	65 (47.4)
Alpha blockers use
No	21 (10.8)	16 (11.7)	0.9
Yes	174 (89.2)	121 (88.3)
Median lobe
No	121 (62.1)	91 (66.4)	0.5
Yes	74 (37.9)	46 (33.6)
TRUS prostate volume
Mean (median)	70 (69)	86 (76)	<0.001
IQR	45–79	57–105
PSA
Mean (median)	5 (2.7)	2.7 (5)	<0.001
IQR	1.2–4.9	2.5–8.3
IPSS
Mean (median)	23 (23)	31 (34)	<0.001
IQR	20–27	29–35
QoL score
Mean (median)	4 (4)	5 (6)	<0.001
IQR	4–5	5–6
Qmax
Mean (median)	6.3 (6)	4 (4)	<0.001
IQR	4–8	3–5
PVR
Mean (median)	185 (180)	590 (530)	<0.001
IQR	70–260	450–710

Bold type means these results reached statistical significance.

5-ARI = 5-alpha reductase inhibitors; ASA = American Society of Anesthesiology; CIC = clean intermittent catheterization; IPSS = international prostate symptom score; IQR = interquartile range; PSA = prostate specific antigen; PVR = postvoid residual; Qmax = maximum urinary flow rate; QoL = quality of life; TRUS = transrectal ultrasonography.

Median prostate volume in the retention strata was 76 cc (IQR 57–105 cc) compared with 69 cc (IQR 45–79) in those without retention (p < 0.001). Presence of median lobe was in 33.6% and 37.9% of patients with and without retention, respectively (p = 0.5). In addition, patients with retention had higher baseline serum PSA (5 ng/dL vs 2.7 ng/dL; p < 0.001), worse IPSS (34 vs 23; p < 0.001), and QoL (6 vs 4; p < 0.001), as well as worse uroflowmetry parameters (Qmax 4 mL/s vs 6 mL/s; p < 0.001 and PVR: 530 cc vs 180 cc; p < 0.001).

Regarding intraoperative characteristics (Table 2), the median operative time (65 minutes vs 51 minutes; p < 0.001), lasing time (35 minutes vs 25 minutes; p < 0.001), as well as the number of irrigation bags (5 vs 4 bags; p < 0.001), were higher in patients with retention relative to patients without retention. Conversely, no statistically significant difference was recorded for energy density (p = 0.2).

Table 2.

Operative Characteristics of 322 Patients Treated with XPS GreenLight Stratified According to Preoperative Retention Status

Variables	No retention (n = 195)	Retention (n = 137)	p
Operative time
Mean (median)	56 (51)	72 (65)	<0.001
IQR	37–66	54–85
Lasing time
Mean (median)	29 (25)	34 (35)	<0.001
IQR	17–36	26–45
Energy use (KJ)
Mean (median)	247 (215)	304 (297)	<0.001
IQR	134–309	197–384
Energy density (kJ/cc)
Mean (median)	3.7 (3.6)	3.8 (3.8)	0.2
IQR	2.7–4.5	2.9–4.7
Number of irrigation bags
Mean (median)	5 (4)	6 (5)	<0.001
IQR	4–6	4–7

Bold type means these results reached statistical significance.

The majority of the surgeries were performed as an outpatient procedure with the Foley catheter removed within 24–48 hours. However, patients with retention experienced longer hospital stay (p = 0.002) and catheterization time (p < 0.001) relative to their counterparts. No statistically significant difference in failure of first void trial was recorded for the two groups. Tables 3 and 4 show intraoperative and postoperative complications stratified according to retention status. There were no statistically significant differences in the intraoperative and 30-day complications rates between the two groups. However, the 90-day complication rate was higher in the nonretention group relative to the retention group (35.4% vs 21.2%; p = 0.02). This difference was attributed to the increased rate of lower urinary tract symptoms requiring medical intervention at 90 days post-PVP (19% vs 5.1%; p < 0.001). There were no Clavien grade 3 complications or higher in either group for the entire duration of the study period.

Table 3.

Intraoperative Complications of 322 Patients Treated with XPS GreenLight Stratified According to Preoperative Retention Status

Variables	No retention (n = 195)	Retention (n = 137)	p
Transfusion	0 (0)	2 (1.5)	0.3
Conversion to TURP	5 (2.6)	5 (3.6)	0.5
Hospital length of stay^a
Mean (median)	0.4 (0)	0.9 (0)	0.002
IQR	0–0	0–1
Range	0–5	0–21
Duration of catheterization^a
Mean (median)	0.9 (1)	1.2 (1)	<0.001
IQR	1–1	1–1
Range	0–7	0–7
First trial to void failure	20 (10.3)	25 (18.2)	0.053

Bold type means these results reached statistical significance.

0: less than 24 hours; 1: between 24 and 28 hours.

TURP = transurethral resection of the prostate.

Table 4.

Postoperative Complications of 322 Patients Treated with XPS GreenLight Stratified According to Preoperative Retention Status

Variables	No retention (n = 195)	Retention (n = 137)	p
Overall 30-day complications	70 (35.9)	40 (29.2)	0.3
Hematuria Clavien I	27 (13.8)	13 (9.5)	0.3
Hematuria Clavien II	1 (0.5)	1 (0.7)	0.6
Hematuria Clavien III	1 (0.5)	1 (0.7)	0.9
Urinary tract infection Clavien II	2 (1)	7 (5.1)	0.06
LUTS Clavien I	22 (11.3)	7 (5.1)	0.08
LUTS Clavien II	4 (2.1)	1 (0.7)	0.6
Urinary incontinence Clavien I	4 (2.1)	0 (0)	0.2
Urinary incontinence Clavien II	2 (1)	0 (0)	0.6
Acute urinary retention Clavien II	10 (5.1)	11 (8)	0.4
30-Day readmission	12 (6.2)	8 (5.8)	0.2
Overall 90-day complications	69 (35.4)	29 (21.2)	0.02
Hematuria Clavien I	3 (1.5)	3 (2.2)	1
Urinary tract infection Clavien II	5 (2.6)	5 (3.6)	0.8
LUTS Clavien I	13 (6.7)	9 (6.6)	0.9
LUTS Clavien II	37 (19)	7 (5.1)	<0.001
Urinary incontinence Clavien I	7 (3.6)	2 (1.5)	0.4
Urinary incontinence Clavien II	6 (3.1)	3 (2.2)	0.9
Acute urinary retention Clavien II	0 (0)	4 (2.9)	0.06
PVP failure (chronic retention requiring chronic Foley or CIC)	4 (2.1)	8 (5.8)	0.1
BPH retreatment	0 (0)	3 (2.2)	0.1

Bold type means these results reached statistical significance.

BPH = benign prostatic hyperplasia; LUTS = lower urinary tract symptoms; PVP = photovaporization of the prostate.

The median follow-up was 24 months. After PVP, IPSS was significantly decreased compared to baseline in both groups. This improvement in IPSS was sustained across all follow-up endpoints (Fig. 1A). Similar trend was observed for QoL (Fig. 1B). Regarding uroflowmetry parameters, PVP provides a durable improvement in patients with or without preoperative retention (Fig. 1C and D). Median PSA reduction rates at 6 and 12 months after PVP were 58% and 49% in patients without retention compared with 62% and 61% in patients with retention (p > 0.05).

FIG. 1.

Symptomatic scores ( A: IPSS and B: QoL) and voiding parameters ( C: Qmax and D: PVR) after PVP. PVP = photovaporization of the prostate.

Regarding surgical failure after PVP, 5.8% and 2.1% of patients with and without retention require long-term permanent or intermittent catheterization (p = 0.1). In addition, 24-month retreatment rates were 2.2% and 0% in patients with and without retention, respectively (p = 0.1). In subgroup analyses of patients with retention, no statistically significant differences in preoperative characteristics (age, history of diabetes, history of neurologic disease, TRUS prostate volume, catheterization type, PVR, and duration of preoperative catheterization) were recorded in patients who failed after PVP relative to their counterparts.

Discussion

This study demonstrated that PVP is an effective and safe treatment option in men presenting with AUR, with a catheter-free rate of 96%. Preoperative AUR was more common in older patients, with higher ASA scores and history of diabetes, all features related to detrusor hypocontractility. Men in preoperative AUR were found to have larger volume prostates and PSA measurements.

Liu and colleagues⁸ evaluated the effects of 2-μm (thulium) laser for treatment of medication refractory urinary retention secondary to BPH. Their study also found that men in the AUR cohort tended to be older, have larger prostates, and a higher PSA compared with those without retention, which are consistent with the findings in our study. These factors were also consistent with Cho and colleagues, who looked specifically at PVP with the 120-W potassium titanyl phosphate (KTP) laser in patients with AUR and found that patients in retention were significantly older and had higher PSA levels and larger prostates.⁹

The increased prevalence of diabetes in our AUR cohort echoed findings found by Woldrich and colleagues who found that patients in AUR had a higher prevalence of diabetes compared with those without retention.¹⁰ The Woldrich and colleagues study also found increased prevalence of heart disease and anticoagulant use in their patients with AUR, which our study did not show. Interestingly 5-alpha reducatase inhibitors (5-ARI) usage in our study was more common in the patients who presented without retention which is consistent with the Medical Therapy of Prostatic symptoms (MTOPS) study and Proscar Long-term Efficacy and Safety Study (PLESS) which both showed decreased rates of AUR in their 5-ARI cohorts.^11,12

Our study presents the first evidence of increased overall 90-day complication rate in patients who undergo PVP who present without retention preoperatively compared with those with AUR. The majority of the complications come from lower urinary tract symptoms (LUTS) Clavien grade II, which were more common in those without retention in our study. This is in contrast to numerous other studies which showed no increase in complication rate between patients with and without retention who proceed with PVP, although all of the studies were limited to 80–120 W KTP laser systems.^10,13

In our study 21.9% of patients were unable to pass their first void trial postoperatively; this is consistent with the published rate of immediate failure after surgery reported as 8%–25% of patients with preoperative AUR. Ultimately, the endpoint data were consistent with over 90% of patients in preoperative AUR able to urinate without the need of a catheter, which is consistent with the published literature.^10,14 Our functional outcomes after PVP also echo that which is published in the literature, with patients with preoperative AUR having improvement of IPSS, QoL, and Qmax to values similar to their nonretention counterparts.^13,15 Of interest, our study found that after PVP, patients in preoperative AUR had a higher PVR than those that were not in preoperative AUR. This may be related to irreversible damage to the bladder secondary to high bladder volumes generated during the episode of AUR, although the clinical significance of this finding is likely negligible.

This study has a number of strengths. This is among the largest cohort of patients in preoperative AUR studied that underwent PVP. In addition, this is the first study, to our knowledge, studying patients with preoperative AUR who underwent PVP using the 180 W KTP laser fiber. Often complications related to TURP concern bleeding due to the prostate volume.¹⁶ Finally, we have follow-up until 24 months, showing the durability of this treatment modality in this patient population with PSA reduction of X% and Y%, which has been demonstrated to correlate well with prostate tissue removal.¹⁷

Our study is subject to a number of limitations. This study was uncontrolled cohort study; therefore, differences between our cohorts cannot be used to discuss prognostic indicators of post PVP failure. Additional limitation is that two different types of fibers were used, which could have biased the results, although the majority of this study was performed using the 180 W KTP laser fiber. Additional limitation is that there were multiple providers providing treatment with varying experience, therefore there can be some slight technical differences. Furthermore, there was an absence of baseline and prior urodynamic features to assess bladder contractility. In terms of diabetes, we did not capture the following: diabetes status (diabetes mellitus [DM] I vs DM II), glycemic controls, duration of disease, and end organ damage.

Conclusion

PVP is an effective, safe, and durable treatment for men in AUR with a catheter-free rate of 93.1%. The improvement is similar to those who did not present in AUR. Higher immediate postop retention and risk of long-term retention should be determined with patient during surgical counseling.

Footnotes

Author Disclosure Statement

No competing financial interests exist.

Abbreviations Used

References

Marshall

, Haber

, Josephson

. An evidence-based approach to emergency department management of acute urinary retention. Emerg Med Pract, 2014; 16:1–20; quiz 21.

Fitzpatrick

, Desgrandchamps

, Adjali

, et al. Management of acute urinary retention: A worldwide survey of 6074 men with benign prostatic hyperplasia. BJU Int, 2012; 109:88–95.

Roehrborn

, Siami

, Barkin

, et al. The effects of combination therapy with dutasteride and tamsulosin on clinical outcomes in men with symptomatic benign prostatic hyperplasia: 4-year results from the CombAT study. Eur Urol, 2010; 57:123–131.

Abrams

, Chapple

, Khoury

, Roehrborn

, de la Rosette

. Evaluation and treatment of lower urinary tract symptoms in older men. J Urol, 2013; 189(1 Suppl):S93–S101.

Wasson

, Reda

, Bruskewitz

, Elinson

, Keller

, Henderson

. A comparison of transurethral surgery with watchful waiting for moderate symptoms of benign prostatic hyperplasia. The Veterans Affairs Cooperative Study Group on Transurethral Resection of the Prostate. N Engl J Med, 1995; 332:75–79.

Lower urinary tract symptoms in men: Management | Guidance and guidelines | NICE. 2015.

Valdivieso

, Meyer

, Hueber

, et al. Assessment of energy density usage during 180 W lithium triborate laser photo-selective vaporization of the prostate for benign prostatic hyperplasia. Is there an optimal amount of kilo-Joules per gram of prostate?. BJU Int, 2016; 118:633–640.

Liu

, Wang

, Gao

, Shan

. Comparison of 120 W 2-μm laser resection of the prostate outcomes in patients with or without preoperative urinary retention. Wideochir Inne Tech Maloinwazyjne, 2016; 11:223–228.

Cho

, Ro

, Kim

, Son

. Preoperative urinary retention increased the risk of urinary retention after photoselective vaporization of the prostate. World J Men's Health, 2015; 33:182–187.

10.

Woldrich

, Palazzi-Churas

, Lakin

, Albo

, Parsons

. Prostate laser vaporization in men with urinary retention. BJU Int, 2011; 108:395–398.

11.

McConnell

, Roehrborn

, Bautista

, et al. The long-term effect of doxazosin, finasteride, and combination therapy on the clinical progression of benign prostatic hyperplasia. N Engl J Med, 2003; 349:2387–2398.

12.

Bruskewitz

, Girman

, Fowler

, et al. Effect of finasteride on bother and other health-related quality of life aspects associated with benign prostatic hyperplasia. PLESS Study Group. Proscar Long-term Efficacy and Safety Study. Urology, 1999; 54:670–678.

13.

Ruszat

, Wyler

, Seifert

, et al. Photoselective vaporization of the prostate: Subgroup analysis of men with refractory urinary retention. Eur Urol, 2006; 50:1040–1049; discussion 1049.

14.

Pradere

, Peyronnet

, Decock

, Brichart

, Bertrand

, Bruyere

. Photoselective vaporization of the prostate in men with refractory urinary retention. Urology, 2015; 86:145–150.

15.

, Gao

, Hong

, Yang

, Cai

, Zhang

. Photoselective laser vaporization prostatectomy for acute urinary retention in China. J Endourol, 2008; 22:539–543.

16.

Ben-Zvi

, Hueber

, Liberman

, Valdivieso

, Zorn

. GreenLight XPS 180 W vs HPS 120 W laser therapy for benign prostate hyperplasia: A prospective comparative analysis after 200 cases in a single-center study. Urology, 2013; 81:853–858.

17.

Tinmouth

, Habib

, Kim

, et al. Change in serum prostate specific antigen concentration after holmium laser enucleation of the prostate: A marker for completeness of adenoma resection?. J Endourol, 2005; 19:550–554.