Assessment of Learning Curves for 180-W GreenLight XPS Photoselective Vaporisation of the Prostate: A Multicentre Study

Background: The learning curve for photoselective vaporisation of the prostate (PVP) has never been assessed accurately. Objective: To compare 180-W GreenLight XPS PVP learning curves for three surgeons with different levels of surgical experience and different institutional backgrounds. Design, setting, and participants: A multicentre retrospective study of the first patients treated with PVP by three operators in three different centres (n = 152 in group 1, n = 112 in group 2, n = 101 in group 3) was conducted. Surgeon 1 had performed >600 PVP procedures (120-W GreenLight HPS laser) since 2007, while surgeons 2 and 3 had no previous experience with GreenLight PVP. Surgeon 1 mainly treats both benign prostatic hyperplasia (BPH) and urologic oncology, surgeon 2 primarily focuses on urologic oncology, and surgeon 3 mostly treats BPH. Surgeon experience was analysed as a continuous variable in terms of consecutive procedures performed. Intervention: PVP using a 180-W GreenLight XPS laser. Outcome measurements and statistical analysis: The learning curve was analysed in terms of changes over time for the following variables: operative time, the vaporisation time/operative time ratio, and the energy delivered/prostate volume ratio. The primary endpoint was a trifecta of (1) energy delivered > 5 kJ/ml of prostate, (2) vaporisation time/operative time ratio of 66-80%, and (3) no postoperative complications. Results and limitations: Patient baseline characteristics differed significantly among the centres in terms of age, prostate volume, and International Prostate Symptom Score (IPSS). Most perioperative outcomes favoured group 1 over group 3 over group 2. Functional outcomes, such as a decrease in IPSS at 1 mo for the first 50 patients (-15 vs -13.6 vs -13.3; p < 0.0001) and an increase in maximum flow at 1 mo for the first 50 patients (+14.2 vs. +7 vs. +9.4; p < 0.0001), favoured group 1 over group 3 over group 2. The trifecta achievement rate was significantly higher in group 3 over group 1 over group 2 (26.7% vs 14.4% vs 5.4%; p < 0.0001). In multivariate analysis adjusting for age, American Society of Anesthesiologists score, and preoperative prostate volume, the only factors predictive of trifecta achievement were surgeon experience (p < 0.0001) and surgeon identity (p < 0.0001). The study limitations include selection bias, short follow-up, and a lack of consensus regarding learning curve assessment and definition. Conclusions: More than 100 PVP procedures were required to reach an intraoperative parameter plateau regardless of surgeon expertise and institutional background. Both surgeon background and expertise seemed to influence perioperative outcomes during the GreenLight XPS PVP learning curve. Patient summary: Both surgeon background and expertise seem to influence perioperative outcomes during the learning curve when using a GreenLight XPS laser for photoselective vaporisation of the prostate. (c) 2017 European Association of Urology. Published by Elsevier B.V. All rights reserved.