The learning curve for holmium laser enucleation of the prostate: a single-center experience

Abstract

Purpose: Holmium laser enucleation of the prostate (HoLEP) is known to have a steep learning curve and, as a result, its clinical usage has limitations. The purpose of this study was to analyze the learning curve and early complications following the HoLEP procedure.

Materials and methods: A retrospective analysis was performed on 161 patients who had undergone the HoLEP procedure for lower urinary tract symptoms suggestive of benign prostatic hyperplasia (BPH) from July 2008 to September 2009. The procedure was done by two surgeons. Perioperatively, enucleated tissue weight, enucleation time, morcellation time, enucleation ratio (enucleation weight/transitional zone volume), and enucleation efficiency (enucleated weight/enucleation time) were analyzed, and early complications were assessed.

Results: Mean enucleation time, morcellation time, and enucleation ratio were 61.3 min (range, 10-180 min), 12.3 min (range, 2-60 min), and 0.66 (range, 0.07-2.51), respectively. In terms of efficiency, enucleation efficiency was 0.32 g/min (range, 0.02-1.25 g/min) and morcellation efficiency was 1.73 g/min (range, 0.1-7.7 g/min). Concerning the learning curve, enucleation efficiency was stationary after 30 cases (p<0.001), morcellation efficiency reached a learning curve at 20 cases (p=0.032), and enucleation ratio had no learning curve in this study. There were several cases of surgery-related complications, including bladder mucosal injury by the morcellator (13%), capsular injury during enucleation (7%), and conversion to a conventional resectoscopy procedure (15%), which showed a reduction in incidence with time.

Conclusions: The learning curve of HoLEP is steep; however, it can be overcome gradually. Further study is necessary with respect to long-term postoperative follow-up.

Keywords: Holmium; Lasers; Learning; Prostate; Prostatic hyperplasia.

FIG. 1

Relationship between groups of cases divided by 10 consecutive patients and efficacy of enucleation (A), efficiency of enucleation (B), and efficiency of morcellation (C). The efficiency of each procedure was calculated as weight of removed tissue in g/min.

FIG. 2

Comparison of operative efficiency between divided cases. Groups of enucleation ratio (A) and enucleation efficiency (B) were divided into the initial 30 cases, 2nd 20 cases, and the latter; groups of morcellation efficiency (C) were divided into the initial 20 cases, 2nd 20 cases, and the latter. Enucleation ratio was calculated by % of retrieved tissue=retrieved tissue weight/transitional zone volume, enucleation efficiency was retrieved tissue weight/enucleation time (g/min), and morcellation efficiency was retrieved tissue weight/morcellation time (g/min). Error bars indicate standard deviation.

FIG. 3

Scatterplots showing the effect of prostate volume in g on holmium laser enucleation of the prostate (HoLEP) efficiency in g/min. Enucleation efficiency per total prostate volume (A), enucleation efficiency per transitional zone volume (B).