Comparison of outcomes of holmium laser versus bipolar enucleation of prostates weighing >80 g with bladder outlet obstruction

Abstract

Transurethral enucleation of the prostate has been increasingly recognized as an effective minimally invasive technique for management of enlarged prostates. We aimed to compare holmium laser enucleation (HoLEP) and bipolar transurethral enucleation (B-TUEP) of large-volume prostates. A prospectively maintained database in two tertiary referral centers was reviewed for patients with HoLEP and B-TUEP for prostates >80 g. Operative data, perioperative complications, and early postoperative outcomes were compared. The study included 101 patients, 70 who underwent HoLEP and 31 who underwent B-TUEP. The operative enucleation rate (weight of adenoma enucleated in g/min) was higher in HoLEP compared to B-TUEP (P < 0.0001). The operative complication rate, hemoglobin drop, and readmission rate were comparable in both groups (P = 0.13, 0.35, 0.29, 0.59, respectively). The HoLEP arm had a shorter hospital stay and shorter catheterization time (P = 0.001, 0.012). Follow-up data showed a lower International Prostate Symptom Score and serum prostate-specific antigen level in the HoLEP group. The incontinence rate was comparable in both groups. In conclusion, both techniques were effective in managing a high-volume prostate, although HoLEP had a shorter enucleation time, better symptom score, lower postoperative prostate-specific antigen level, shorter catheterization time, and shorter hospital stay compared to B-TUEP.

The choice of surgical technique for management of an enlarged prostate depends on prostate size, associated comorbidities, tolerance of anesthesia, patient preference, availability of the surgical armamentarium, surgeon experience, and familiarity with surgical techniques.^1,2 Large-volume prostates still represent a challenge, with limited surgical treatment options and a preserved role for open/simple prostatectomy when there is unavailability of or inexperience with prostate enucleation techniques. Transurethral enucleation and morcellation of the prostate have been increasingly used as an effective minimally invasive technique for managing large-volume prostates with minimal perioperative morbidity.³ In comparison to the traditional prostate resection techniques, the enucleation technique has shown greater efficacy, a lower recurrence rate, a larger percentage of prostate tissue removed, and minimal blood loss.^3–5 Guidelines recommend prostate enucleation as the first treatment choice for men with large-volume prostates.^1,6 Prostate enucleation has been performed using bipolar electrocautery (plasmakinetic) technology, holmium laser, and thulium laser.^7–9 In this study, we aimed to compare the efficacy, technical aspects, and early postoperative outcomes of holmium laser enucleation of the prostate (HoLEP) and bipolar transurethral enucleation (B-TUEP) for large-volume prostates.

METHODS

After obtaining institutional review board approval (no. 021-238), we gathered data from a prospectively maintained REDCap database for patients in two institutions who underwent HoLEP or B-TUEP for voluminous prostate >80 g between June 2018 and August 2020. HoLEP and B-TUEP have been performed by two surgeons (MET and OFE), both of whom have a high degree of experience in the assigned technique. The first 50 cases of each surgeon were excluded to eliminate a learning curve bias.

The study included patients who underwent prostate enucleation for moderate to severe lower urinary tract symptoms—based on an International Prostate Symptom Score (IPSS) ≥8, uroflowmetry with maximum flow rate (Q max) <10 mL/sec, and acute or chronic urine retention—with at least 6 Januarys of follow-up after enucleation. Patients with a history of previous transurethral surgery before enucleation, urethral stricture, prostate cancer, or neurogenic bladder were excluded. Prostate volume was assessed preoperatively using transrectal ultrasound. The operative time required for enucleation and for morcellation were separately identified, excluding the time required to address any bladder stones.

Enucleation was performed in both arms using a similar enucleation technique, a bilobe or trilobe technique, according to the presence of a significant median lobe. Early apical dissection of the adenoma was performed to protect the sphincter region from further traction during the enucleation maneuvers. Enucleation was conducted as a combination of gentle mobilization with the tip of the resectoscope and cutting whenever necessary. HoLEP was performed using 80 and 40 W holmium laser settings at a power setting of 2J and frequency of 40 and 20 Hz, respectively. Lumenis MOSES™ Pulse technology was adopted beginning in June 2019 for the HoLEP arm. Morcellation was performed for HoLEP using the Piranha^TM morcellator system (Richard Wolf GmbH, Knittlingen, Germany). For B-TUEP, the TURis^TM Plasma vaporization with oval button technology (Olympus, Hamburg, Germany) was used for enucleation, while morcellation was performed with the Versacut^TM morcellator system (Lumenis GmbH, Dreieich-Dreieichenhain, Germany).

We compared baseline preoperative data, operative details including enucleation and morcellation time, prostate morcellation weight, perioperative complications, and postoperative outcomes at 6-week and 6-January follow-up in both groups. The primary endpoint of the study was operative time in correlation to weight of the resected gland (enucleation rate in g/min = weight of enucleated adenoma/enucleation time), while other intraoperative and postoperative outcome data were considered secondary endpoints.

For descriptive statistics, continuous variables were presented as mean (standard deviation) or median (interquartile range) according to normality, while categorical variables were given as absolute numbers and percentages. For statistical analysis, two-sample t tests or Wilcoxon rank sum tests were used for univariate analysis of quantitative variables, while chi-square tests or Fisher’s exact tests were used for categorical variables according to the expected cell counts. The significance level was set at a P value < 0.05.

RESULTS

The study included 101 patients who met inclusion criteria, with 70 in the HoLEP arm and 31 in the B-TUEP arm. The HoLEP group had a higher mean age (P = 0.0002), while the B-TUEP group had a higher percentage of patients with preoperative urine retention (P = 0.025). Otherwise, both groups had comparable baseline data (Table 1). The operative enucleation rate was calculated in both groups by correlating the weight of the enucleated adenoma to enucleation time. Enucleation rate in g/min was significantly higher in the HoLEP group than the B-TUEP group (P < 0.0001), meaning that HoLEP was associated with a shorter operative time. The weight of tissue gained in correlation to estimated preoperative prostate volume was also compared, showing a comparable percentage of tissue enucleated in both groups (P = 0.13).

Table 1.

Preoperative baseline data

Variable	HoLEP (N = 70)	B-TUEP (N = 31)	P value
Age (years), mean ± SD	70.2 ± 8.2	64.2 ± 7	0.0002
Prostate volume (g), median (IQR)	108 (92–144)	103 (89–140)	0.23
Preoperative IPSS, mean ± SD	21.1 ± 7.7	22.8 ± 6	0.13
Preoperative QOL, mean ± SD	5 ± 0.6	4.8 ± 0.6	0.72
PVR (mL), median (IQR)	124.5 (58–275)	180 (100–480)	0.09
Preoperative retention	34 (48.5%)	22 (71%)	0.025
PSA (ng/mL), mean ± SD	8.4 ± 10.1	8.4 ± 6.8	0.96
Preoperative Hb (g/dL), mean (SD)	13.9 ± 1.7	13.4 ± 1.6	0.15
Anticoagulant use	21 (30%)	5 (16%)	0.0765
Associated bladder stones	4 (6%)	3 (10%)	0.441

B-TUEP indicates bipolar transurethral enucleation; Hb, hemoglobin; HoLEP, holmium laser enucleation; IPSS, International Prostate Symptom Score; IQR, interquartile range; PSA, prostate-specific antigen; PVR, postvoid residual; QOL, quality of life; SD, standard deviation.

Patients in both cohorts achieved postoperative voiding with satisfactory urine residual. Operative complication rate, postoperative hemoglobin drop (preoperative – postoperative), and readmission rate were comparable in both groups (P = 0.13, 0.35, 0.29, 0.59, respectively). Intraoperative complications were bladder mucosal injury in three patients and limited capsular perforation in one patient. Catheterization time and length of hospitalization were significantly lower in the HoLEP group (P = 0.012, <0.001, respectively), while early hospital postvoid residual was lower in the B-TUEP group (P = 0.017) (Table 2). The grade of Clavien-Dindo complications within 30 postoperative days was comparable in both groups (Table 3). Clavien-Dindo class I included mainly hematuria or urine retention requiring reinserting a urethral catheter or prolonged catheterization. Class II complications were mainly urinary tract infection or blood transfusion, while class III complications included two cases of postoperative cystoscopy for clogged catheter with difficult recatheterization and hematuria in HoLEP and B-TUEP, respectively. In the HoLEP group, two patients were readmitted within 30 days for hematuria and clot retention.

Table 2.

Perioperative outcome data

Variable	HoLEP (N = 70)	B-TUEP (N = 31)	P value
Enucleation rate (g/min), mean ± SD	1.9 ± 1	1.1 ± 0.4	<0.001
Adenoma enucleated percentage, mean ± SD	70.4 ± 27	64.3 ± 18	0.13
Operative complications	2 (2.8 %)	2 (6.4%)	0.241
Hemoglobin drop (g), mean ± SD	1.8 ± 1.3	1.5 ± 1.1	0.29
Catheterization (days), median (IQR)	1 (1–2)	2 (2–3)	0.012
Hospital stay (days), mean ± SD	1.2 ± 0.7	1.9 ± 0.6	<0.001
Early PVR (mL), median (IQR)	26.5 (3.5–67)	12 (0–35)	0.017
Readmission	2 (2.8%)	0	0.39

B-TUEP indicates bipolar transurethral enucleation; HoLEP, holmium laser enucleation; IQR, interquartile range; PVR, postvoid residual; SD, standard deviation.

Table 3.

Comparison of 30-day Clavien-Dindo perioperative complications

Complication grade	HoLEP	B-TUEP	P value
I	6 (8.5%)	5 (5.17%)	0.473
II	4 (5.7%)	1 (2.3%)
IIIa	1 (1.4%)	0
IIIb	0	1 (0.56%)
Overall	11 (15.7%)	7 (22.3%)	0.405

B-TUEP indicates bipolar transurethral enucleation; HoLEP, holmium laser enucleation.

Postoperative follow-up data showed a significantly lower IPSS with HoLEP at both 6 weeks and 6 Januarys (P = 0.002, 0.034), although this was not reflected in a difference in quality of life. The prostate-specific antigen level 3 to 6 Januarys after the procedure was significantly lower in the HoLEP group (P = 0.0072). Stress and urge incontinence rates and pad use were comparable in both groups, as shown in Table 4. Linear regression analysis for operative and postoperative outcomes, controlling for age, preoperative prostate volume, and preoperative retention, showed the same significance results.

Table 4.

Postoperative follow-up data

Variable		HoLEP (N = 70)	B-TUEP (N = 31)	P value
6-week follow-up	IPSS, mean ± SD	7.5 ± 5.2	10.7 ± 3.9	0.002
	QOL, mean ± SD	1.9 ± 2.3	2.1 ± 0.9	0.4146
	Urge incontinence	12 (17.1%)	2 (6.5%)	0.1784
	Stress incontinence	16 (22.8%)	7 (22.6%)	0.8823
	Pads used (n), mean ± SD	1.3 ± 1.4	2.1 ± 1.9	0.1459
6-month follow-up	IPSS, mean ± SD	4.9 ± 3.6	6.6 ± 3.6	0.034
	QOL, mean ± SD	1.3 ± 1.4	1.6 ± 0.7	0.2243
	Urge incontinence	4 (5.7%)	0 (0%)	0.3666
	Stress incontinence	4 (5.7%)	2 (6.5%)	1.000
	Pads used (n), mean ± SD	1.6 ± 1.8	2.5 ± 0.7	0.5151
Postop PSA (ng/mL), median (IQR)		0.5 (0.3–1)	0.9 (0.5–1.8)	0.0072

B-TUEP indicates bipolar transurethral enucleation; HoLEP, holmium laser enucleation; IPSS, International Prostate Symptom Score; IQR, interquartile range; PSA, prostate-specific antigen; QOL, quality of life; SD, standard deviation.

DISCUSSION

The prostate enucleation technique has the advantage of less blood loss, shorter operative time, higher tissue yield, greater efficacy, and lower recurrence rate compared to the traditional transurethral resection of prostate (TURP) and other minimally invasive transurethral procedures. These advantages are more obvious in cases with a large-volume prostate.^3,4,10,11

The most commonly utilized prostate enucleation modalities are holmium laser (HoLEP), bipolar diathermy (B-TUEP), and thulium laser (ThuLEP). When HoLEP was compared to open prostatectomy for prostate size >100 g, it showed significantly less blood loss and shorter catheterization time and hospital stay, although it was associated with a longer operative time. Long-term follow-up data showed comparable efficacy and a similar low reoperation rate.^12,13 B-TUEP has also shown minimal complications and less perioperative morbidity with comparable long-term efficacy in comparison to open prostatectomy for a large-volume prostate.^14,15

Magistro et al compared B-TUEP, HoLEP, and TURP for management of a medium-sized prostate (50 cc ± 5) in a three-arm matched retrospective study. They identified superior perioperative and functional outcomes with enucleation techniques compared to TURP with no relevant difference of clinical outcomes between HoLEP and B-TUEP.⁶ Neill et al compared HoLEP and B-TUEP in a prospective randomized study involving 40 patients with average prostate volume of 57 cc. They reported better visualization, shorter operative time, and less bladder irrigation requirement in the HoLEP group.¹⁶ In a systematic review and meta-analysis of studies comparing laser energy vs bipolar plasmakinetic technology in transurethral prostate surgery (enucleation or resection) in general, Gi et al found that early efficacy and safety profiles were comparable, with less reduction in hemoglobin, shorter catheterization duration, and shorter hospital stay in favor of lasers.¹⁷ Feng et al compared B-TUEP and ThuLEP in a prospective trial showing comparable efficacy and safety, although there was a lower risk of hemorrhage and shorter catheter time with ThuLEP compared to B-TUEP.¹⁸ Among studies that have compared HoLEP and ThuLEP, most showed comparable perioperative and postoperative outcomes, with a proposed minor advantage of ThuLEP related to blood loss, operative time, and transient incontinence by some studies.^19–21

Patard et al²² recently compared HoLEP and B-TUEP in management of prostates >60 g. They reported the superiority of B-TUEP in the form of shorter operating, catheterization, and hospitalization times. In contrast to the results of Patard et al,²² our results showed that both techniques demonstrated great efficacy for management of a high-volume prostate, although HoLEP was significantly associated with a shorter operative time (primary endpoint), a lower IPSS, shorter catheterization time, and shorter hospital stay. With adoption of Lumenis MOSES™ Pulse technology, which offers better hemostatic and energy transmission properties, in the HoLEP arm, early catheter removal at postoperative day 0 to 1 and outpatient operative strategy were adopted in appropriate patients. This may reflect the shorter hospital stay and shorter catheterization time in the HoLEP group, although early catheter removal in the HoLEP arm was associated with a significantly higher initial postvoid residual compared to the B-TUEP group. The current study is limited by its retrospective nature, although the patients in both groups were prospectively managed with data maintained.

In conclusion, HoLEP is associated with shorter operative time, better symptom score, shorter catheterization time and hospital stay, and lower postoperative prostate-specific antigen level compared to B-TUEP for management of the enlarged prostate gland. Otherwise, both techniques are very effective for large-volume prostate enucleation, with comparable operative and early postoperative outcomes.