Analysis of Holmium Laser Enucleation of the Prostate in a High-Volume Center: The Impact of Concomitant Holmium Laser Cystolitholapaxy

Abstract

Purpose:

To assess the influence of holmium laser cystolitholapaxy (HLC) concomitantly with holmium laser prostate enucleation (HoLEP) on patients with benign prostatic hyperplasia (BPH) presenting bladder calculi.

Materials and Methods:

We present a retrospective analysis of patients with BPH (with or without concomitant HLC) at three Spanish centers. Intraoperative variables (e.g., time and resected tissue), changes in functional parameters of the prostate, and frequency of complications (intraoperative, early postoperative, and at 12 months) in patients with and without HLC were compared.

Results:

The analysis included 963 patients aged 48 to 91 years, of which 54 (5.6%) underwent HLC to treat vesical lithiasis. Mean (range) prostate size (measured by transrectal ultrasound) was 79 (43–173) g and 91 (35–247) g for patients with and without concomitant HLC, respectively (p = 0.080). All bladder calculi were effectively removed. No significant differences were found regarding enucleation and morcellation times, but total operation time was significantly higher in patients with HLC: mean (standard deviation [SD]) of 78 (27) minutes vs 95 (41) minutes (p < 0.001). Three patients underwent conversion to open surgery because of bladder perforation, all of them from the group without HLC. Rates of intraoperative, early, and 12-month complications were similar in both groups. No significant differences in International Prostate Symptom Scale, maximum flow rate (Qmax), and mean flow were observed between groups 12 months after surgery.

Conclusions:

Simultaneous HoLEP and HLC increases the total operation time, but does not influence the risk of clinically relevant perioperative and postoperative complications.

Introduction

Benign prostatic hyperplasia (BPH) is an age-related condition eventually developed by >80% of men in their 70s and 80s.¹ Surgical removal of the prostate is the recommended treatment for patients with some clinical manifestations and an absolute indication for those diagnosed with other concomitant BPH-associated conditions, such as bladder lithiasis.^2

–5

In the past few years, multiple surgical techniques to treat BPH have become available. The choice of the surgical technique depends on various factors, including prostate size, ability to have anesthesia, patient's preferences, willingness to accept specific surgery-associated side effects, availability of surgical armamentarium and skills, and comorbidities of the patient (including vesical lithiasis).⁴ Among the available techniques to treat BPH, open prostatectomy (OP) is the most effective—although more invasive—followed by transurethral resection of the prostate (TURP), which is less invasive but only suitable for small prostates (<80 g).⁴ To date, these techniques are considered standard treatments for BPH, despite being associated with significant morbidity.^4,6,7

In the past years, less invasive and yet effective endoscopic laser-based surgical techniques, including thulium:yttrium–aluminum–garnet (or thulium), KTP (Potassium Titanyl Phosphate) (GreenLight 532 nm), laser prostate vaporization, and holmium laser prostate enucleation (HoLEP), have emerged.^4,8 HoLEP is as effective as OP for prostates >80 g, and results in shorter catheterization time and hospital stay, in addition to causing minimal bleeding because of the hemostatic properties of the holmium laser.^3,4 Thus, HoLEP has been proposed as the new gold standard for BPH, and the European Association of Urology recommends HoLEP as the first-choice surgical treatment in men with large prostates (>80 g) whenever available.^4,9,10 Additional advantages of holmium laser include its capacity to rapidly fragment bladder calculi of any size, while causing minimal hematuria and damage to the bladder mucosa compared with mechanical lithotripsy. This feature, missing in other marketed lasers (i.e., thulium and GreenLight), allows for a feasible and effective transurethral holmium laser cystolitholapaxy (HLC), which could be potentially performed simultaneously with HoLEP.^5,8,11
–13 However, the significant initial cost of the holmium laser equipment and the prolonged learning curve of the technique have limited a broad implementation of this advanced technology in routine practice.^10,14,15

Despite the advantages of the holmium laser for HoLEP and HLC, studies about the simultaneous use of these techniques in patients with BPH and concomitant bladder lithiasis are scarce.^9,13,16 As a result of our enucleation program implemented in three centers in Madrid (Spain), a large series of BPH patients with large prostate volumes and high comorbidity burden, including patients with concomitant urolithiasis, were collected. This study retrospectively assessed the impact of concomitant treatment of bladder lithiasis with HLC on perioperative and postoperative outcomes in patients with BPH undergoing HoLEP.

Material and Methods

Study design and population

This was a retrospective analysis of a registry of patients with BPH treated with HoLEP within the framework of a local enucleation program. This registry was built prospectively by including consecutive patients admitted between January 2007 and December 2016 in three centers in Madrid (Spain): Hospital Universitario 12 de Octubre, Hospital Universitario Montepríncipe, and Hospital La Luz. Patients were included if they were >18 years of age, had a positive preanesthesia assessment, and gave consent for the surgery. Patients with suspected prostatic neoplasia at the transitional zone, bladder diverticulum, ureteral stones, bladder tumor, or urethral stricture, requiring other concomitant operations during the same procedure, were excluded from the study. Other exclusion criteria were previous history of urethral stricture or prostatic surgery and active hematuria. When prostatic neoplasia was suspected because of prostate-specific antigen (PSA) levels and/or digital rectal examination, a biopsy was performed before surgery. If negative, the patient was scheduled for HoLEP and included in the analysis.

The variables considered for this study—baseline characteristics, intraoperative, and early postoperative outcomes, and follow-up outcomes, which were assessed during hospital stay and at 12 months after the surgery, respectively—were retrieved from the database. All participants signed the corresponding informed consent before study inclusion. The study was conducted in accordance with the Helsinki Declaration and the local Personal Data Protection Law (LOPD 15/1999); the study protocol was approved by the local independent ethics committee.

Surgical procedure

Surgeries were performed by the same two surgeons in the three centers following the prostatic enucleation technique as initially described by Gilling et al.¹⁷ and modified by Kuntz et al.¹⁸ The equipment included a 100 W holmium laser (Lumenis, Inc.^®, Palo Alto, CA) with a reusable 550 nm laser fiber, a 26F continuous-flow resectoscope (Storz^®), a 27F nephroscope with a 5 mm working channel, a morcellator (Versacut, Lumenis, Inc.), normal saline irrigation, and a video system. If bladder calculi were observed during the HoLEP procedure, cystolitholapaxy was performed before HoLEP using the same instrument. To pulverize the bladder calculi, the energy was set at 1–3 J and 20–40 Hz, reaching 20–100 W, although it varied depending on the number, size, and hardness of the calculi. The residual fragments were extracted using a Toomey Syringe.

Outcomes and variables

The primary objective was to compare the outcome of patients only undergoing HoLEP with that of patients with simultaneous HLC. Baseline variables included patient demographic and clinical characteristics: age; medical history; including relevant concomitant diseases, such as diabetes mellitus, arterial hypertension, neuropathy, and vasculopathy; whether the patient is a bladder catheter carrier; concomitant antithrombotic therapies (anticoagulants and platelet inhibitors); and the American Society of Anesthesiologists score. Baseline and follow-up functional assessments included prostate size—measured by external and transrectal ultrasound—PSA concentration, maximum flow rate (Qmax), and mean flow rate and urinary condition using the validated International Prostate Symptom Scale (IPSS). Intraoperative variables included total time in surgery, time for enucleation and morcellation, and weight of resected tissue. The following intraoperative complications were considered clinically significant for study purposes: bladder and/or capsule perforation, significant bleeding (considered as bleeding severe enough to prompt a modification of the operation plan), urethral lesion, instrument malfunction, and reconversion to transurethral resection (TUR) or OP. Other surgical variables, such as total hospital stay, time with urinary catheter, and whether concomitant bladder lithiasis treatment was needed, were also recorded. Postoperative complications included reoperation and reason, readmission and reason, total visits to the emergency room and reason—hematuria, acute urinary retention (AUR), urinary tract infection (UTI), and others— and whether a transfusion was needed. Complications recorded at follow-up included urethral stricture and stress incontinence, and their treatment.

Statistical analysis

Categorical variables were presented as frequencies and percentages, whereas quantitative variables were presented as mean and SD or range. Categorical values were compared using Fisher's exact test or the chi-square test. To evaluate the functional outcome, variables were measured at two different time points: before and after surgery. Pre- and postoperative values were compared using the paired-samples t-test after confirming the normal distribution of the differences using the Kolmogorov–Smirnov test. The significance threshold for all bivariate analyses was set at a two-sided α = 0.05. All statistical analyses were performed using the SAS software.

Results

Clinical characteristics of study patients

Of a total of 1152 patients undergoing HoLEP during the study period at the participating sites, 189 were excluded from the analysis for not meeting the selection criteria: 73 were lost to follow-up, 3 underwent concomitant diverticulectomy, 62 had been previously operated on for BPH using another surgical technique, 11 underwent concomitant urethrotomy, 27 needed concomitant TURB, 3 underwent concomitant ureterorenoscopy, and 10 were excluded for other reasons. Thus, the final study sample included 963 patients, of which 54 (5.6%) had concomitant vesical lithiasis. No significant differences in age were found between patients with vesical lithiasis (mean of 74 years, range 48–91) and patients without it (mean of 70 years, range 46–86) (p = 0.34). Table 1 summarizes the study patient clinical characteristics at baseline based on the presence of vesical lithiasis. Clinical characteristics of both groups were not significantly different, except for the diagnosis of neuropathy and catheterization before surgery, which were more frequent among patients with and without vesical lithiasis, respectively (Table 1).

Table 1.

Clinical Characteristics of Study Patients Based on a Diagnosis of Bladder Lithiasis

	Without HLC (n = 909)	With HLC (n = 54)	p
Catheterized presurgery, n (%)	332 (36)	11 (20)	0.032
Prostate size (external ultrasound) (g), mean (range)	102 (40–316)	90 (42–220)	0.070
Prostate size (transrectal ultrasound) (g), mean (range)	91 (35–247)	79 (43–173)	0.080
IPSS, mean (range)	23.2 (14–30)	26.1 (18–30)	0.300
Qmax (mL/s), mean (range)	7.2 (0–16)	5.2 (0–14)	0.210
PSA (ng/dL), mean (range)	6.02 (0.3–43.5)	5.12 (0.5–18)	0.080
Comorbidities, n (%)
Diabetes mellitus	165 (18)	8 (14)	0.280
Hypertension	502 (55)	28 (51)	0.190
Neuropathy	61 (7)	9 (17)	0.041
Vasculopathy	36 (4)	1 (2)	0.630
Concomitant treatments, n (%)
Anticoagulants	98 (11)	8 (15)	0.410
Antiplatelets	256 (28)	14 (26)	0.530
American Society of Anesthesiologists score
1	54 (5.9)	1 (2)	0.250
2	544 (56.5)	28 (52)	0.310
3	332 (34.5)	21 (39)	0.230
4	28 (2.9)	4 (7)	0.080

Bold values indicate statistical significance.

HLC = holmium laser cystolitholapaxy; PSA = prostate-specific antigen; IPSS = International Prostate Symptom Scale, Qmax = maximum flow rate.

Perioperative variables

All bladder calculi in patients with vesical lithiasis were effectively removed using HLC, regardless of their size and composition. No significant differences were found between patients with and without HLC regarding enucleation time, morcellation time, and resected tissue (Table 2). However, total operation time was significantly higher in patients with HLC than in patients without HLC (mean difference of 17 min). Likewise, no significant differences were found regarding the length of hospital stay (mean [SD] was 4 [2] days for both groups; p = 0.65) and time with urinary catheter (mean [SD] was 1.4 [2] and 1.3 [2] days for patients with and without concomitant HLC, respectively; p = 0.57).

Table 2.

Intraoperative Variables of Study Patients Based on a Diagnosis of Bladder Lithiasis, Mean (Standard Deviation)

	Without HLC (n = 909)	With HLC (n = 54)	p
Total operation time (minutes)	78 (27)	95 (41)	0.001
Enucleation time (minutes)	39 (13)	34 (16)	0.420
Morcellation time (minutes)	26 (11)	21 (16)	0.610
Resected tissue (g)	75 (19)	69 (22)	0.110

Bold value indicates statistical significance.

Treatment outcome and follow-up

Most frequent complications related to BPH surgery, classified into intraoperative, early postoperative, and follow-up, were similar irrespective of concomitant HLC (Table 3). Remarkably, no patients undergoing simultaneous HLC experienced bladder perforation or TUR syndrome. Similarly, the frequency of early postoperative complications, including hematuria, AUR, cloth retention, sepsis, and UTI, did not change significantly in patients with concomitant HLC.

Table 3.

Surgery-Related Complications Based on a Diagnosis of Bladder Lithiasis, n (%)

	Without HLC (n = 909)	With HLC (n = 54)	p
Intraoperative
Capsule perforation	11 (1.2)	1 (1.9)	0.860
Bladder perforation	3 (0.3)	0	0.750
TURP syndrome	4 (0.4)^a	0	0.660
Conversion
Conversion to TURP	30 (3.3)	3 (5.6)	0.410
Owing to instrument malfunction	7 (0.8)	2 (3.7)	0.090
Owing to inability to complete HoLEP	26 (2.9)	1 (1.9)	0.210
Conversion to open surgery	3 (0.3)^b	0	0.750
Early postoperative
Hematuria	69 (7.6)	3 (5.6)	0.690
Surgical hemostatic review	16 (1.8)	1 (1.9)
Acute urinary retention	35 (3.9)	7 (13)	0.150
Clot retention	2 (0.2)	0
Transfusion	47 (5.1)	2 (3.7)	0.490
Sepsis	1 (0.1)	1 (1.9)	0.780
Urinary tract infection	28 (3.1)	4 (7.4)	0.520
Readmissions	15 (1.6)	2 (3.7)	0.630
At 12-month follow-up
Urethral stricture, distal	13 (1.4)	2 (3.7)	0.190
Urethral stricture, bulbar	18 (2.0)	5 (9.3)	0.070
Stress incontinence	20 (2.2)	2 (3.7)	0.270

Two patients underwent dialysis.

All cases were caused by bladder perforation.

HoLEP = holmium laser prostate enucleation; TURP = transurethral resection of the prostate.

The frequency of complications assessed at 12-month follow-up (i.e., urethral stricture and stress incontinence) was comparable, and similar treatments were required in patients with and without HLC: endoscopic urethrotomy (4 [7.4%] vs 10 [1.1%]), meatotomy (2 [3.7%] vs 15 [1.7%]), dilatation (1 [1.9%] vs 11 [1.2%]), and T-T urethrectomy (0 vs 2 [0.2%]). Of 22 patients with stress urinary incontinence (SUI), those who had undergone concomitant HLC (n = 2; 3.7%) managed the complication using incontinence pads, whereas in the group of patients without HLC, 16 patients (1.8%) managed SUI using incontinence pads and 4 (0.4%) underwent surgery: 1 (0.1%) ATOM implant and 3 (0.3%) suburethral slings. None of the patients with HLC experienced major complications, whereas one (0.1%) patient without HLC underwent bilateral ureteral reimplantation.

The functional evaluation 12 months after surgery, which included IPSS, Qmax, and mean flow, yielded similar results in patients with and without concomitant HLC. Similarly, the reduction in prostate size and PSA concentration was similar regardless of HLC (Table 4).

Table 4.

Postoperative Functional Evaluation Based on a Diagnosis of Bladder Lithiasis, Mean (Standard Deviation) Pre/Postoperative Differences

	Pre/postoperative difference without HLC (n = 909)	Pre/postoperative difference with HLC (n = 54)	p
IPSS	−15 (2.6)	−17 (2.9)	0.610
PSA (ng/dL)	−4.61 (1.8)	−3.9 (1.9)	0.540
Qmax (mL/s)	+9.9 (1.2)	+9.1 (1.7)	0.390
Mean flow (mL/s)	+5.8 (3.2)	+5.0 (3.1)	0.130
Prostate size (g)	−57.6 (17.5)	−49.6 (18.7)	0.110

Discussion

This retrospective analysis of 963 patients undergoing HoLEP surgery for BPH provided evidence that concomitant treatment of bladder lithiasis with HLC does not influence intraoperative variables, with the exception of total operation time, which was significantly longer in patients undergoing simultaneous HLC. Functional outcome and complications associated with BPH surgery, including early intraoperative, perioperative, and follow-up complications, were similar in patients undergoing HoLEP, irrespective of simultaneous treatment for bladder lithiasis up to 12 months after surgery, supporting the feasibility of simultaneous HoLEP and HLC.

Despite the increased complexity of combining two procedures in the same surgery, mean time for HoLEP (i.e., enucleation and morcellation) in patients with concomitant HLC (55 minutes) was below that reported in other studies only performing HoLEP (68.4–102.7 minutes).^9,19 Furthermore, morcellation time was similar in patients with and without simultaneous HLC (26 vs 21 minutes), suggesting that the residual fragments of calculi that remained in the bladder after HLC did not hinder subsequent morcellation of prostate tissue. Mean total operation time for patients who underwent concomitant HLC in our cohort (95 minutes) was similar to that reported previously in a series of 32 patients simultaneously treated with HoLEP and HLC (98 minutes).¹³ As expected, this time was significantly higher than that of patients without concomitant HLC (17 minutes longer, similar to the 26 minutes reported by Tangpaitoon et al.).¹⁶ Overall, operation times reported for HoLEP and HLC are similar to those for TURP combined with transurethral or suprapubic removal of bladder calculi (mean range of 65.7–107.23 minutes), but lower than those for Green Laser PVP and HLC (mean range of 115–301 minutes).^{20

–27} It is noteworthy, however, that although TURP-based surgical approaches are often shorter, this procedure is more invasive and unsuitable for large prostates (i.e., >80 g).⁴

The longer operation time in patients undergoing simultaneous treatment for BPH and bladder lithiasis did not result in increased rates of intraoperative and early postoperative complications. Clinically relevant intraoperative complications (i.e., blood transfusion, hematuria, and TUR syndrome) and those causing surgery conversions (i.e., significant bleeding and bladder perforation) showed similar rates irrespective of HLC. Indeed, all surgery conversions were caused by instrument malfunction or inability to complete HoLEP. Even though the heterogeneity of postoperative complications reported in other studies precludes direct comparisons, complication rates for the simultaneous treatment of BPH and bladder lithiasis in our cohort were overall similar to those of previous studies, with the exception of UTI and AUR rates, which were 7.4% and 13% (respectively) in our study patients, and 3% in a previous series using the same technique.¹³ These differences could be explained by the higher comorbidity burden of our study patients, most of which were transferred from other centers because of their complexity.

Time with catheter was similar in patients with and without bladder lithiasis, and similar to the time reported in other studies (<1.9 days for this and other studies).^13,16 However, mean total hospital stay for our study patients (4 days) was longer than that reported by other authors (1.5 days).^13,16 These differences may be attributed to differences in discharge criteria between health care systems. Furthermore, the complexity and comorbidity burden of our study patients may have contributed to extend their hospital stay despite the absence of perioperative complications. Indeed, previous studies have concluded that patients treated with HoLEP, who have to deal with other comorbidities, require longer hospital stays.¹⁵

In addition to early postoperative complications, surgical treatment of BPH is associated with long-term complications that can negatively impact patients' quality of life, including urethral stricture and SUI. In line with other studies using simultaneous HoLEP and HLC, it was found that the frequency of urethral stricture at 12 months was not significantly different between patients with and without bladder lithiasis.^13,16 Likewise, persistent SUI was not significantly different between study groups. The same trend was reported in a previous series, although using different criteria for measuring the incidence of SUI.¹⁶

This study must be considered in the context of the potential selection bias of study patients. As discussed before, most of our patients had been transferred from other centers because of their higher complexity. As a result, some characteristics, such as prostate size, were higher than the average for the overall population undergoing HoLEP, thus shifting the scope of our results to a more severe population. Another potential source of bias includes some differences in baseline characteristics of both groups, specifically regarding the frequency of neuropathy and previous catheterization. However, these differences were considered unlikely to strongly influence the outcomes of both groups. Finally, our study lacks evaluations of long-term outcomes, including late complications (i.e., bladder neck contracture, erectile dysfunction, retrograde ejaculation, and retreatment). Given that previous studies reported remarkably good outcomes at 5-year follow-up for HoLEP, and that short-term outcomes of patients treated with HoLEP and HLC are similar in this and other studies, optimal long-term outcomes for our study patients are expected.¹⁵ Nevertheless, accurate comparisons between long-term outcomes await future evaluation.

Conclusions

In summary, our study shows that simultaneous HoLEP and HLC is an effective and safe option for the treatment of BPH and concomitant vesical lithiasis, and represents and advantageous option to the current gold standard techniques, which are associated with significant morbidity. Although simultaneous treatments increase total operation time, this effect does not influence the risk of clinically relevant perioperative and postoperative complications. Our results support the use of the holmium laser to concomitantly treat BPH and vesical lithiasis without causing additional complications, and this may represent another factor favoring the compensation of its initial high cost and prolonged learning curve.

Footnotes

Acknowledgment

The authors thank i2e3 Biomedical Research Institute for providing medical writing assistance during the preparation of the article.

Disclaimer

All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards. For this type of study formal consent was not required.

Author Disclosure Statement

No competing financial interests exist.

Abbreviations Used

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