Enucleation ratio efficacy might be a better predictor to assess learning curve of holmium laser enucleation of the prostate

Purpose: To appraise the evaluation methods for learning curve and to analyze the non-mentor-aided learning curve and early complications following the holmium laser enucleation of the prostate. Materials and Methods: One-hundred and forty (n=140) consecutive patients who underwent HoLEP from July 2008 to July 2010 by a single surgeon (SJO) were enrolled. Perioperative clinical variables, including enucleation time, morcellation time, enucleation ratio (enucleation weight/transitional zone volume), enucleation efficacy (enucleated weight/enucleation time), enucleation ratio efficacy (enucleation ratio/enucleation time), and early complication rate were analyzed. Results: Mean prostate volume was 62.7 mL (range 21-162) and preoperative International Prostate Symptom Score (IPSS) was 19.0 (4-35). Mean enucleation time and morcellation time were 49.9 +/- 23.8 (S. D.) min and 11.0 +/- 9.7 min, respectively. Median duration of postoperative indwelling catheter was 1 (1-7) day and median hospital stay was 1 (1-6) day. There were a total of 31 surgery-related complications in 27 patients (19.3%), and all were manageable. There was an increasing trend of enucleation efficacy in the first 50 cases. However, enucleation efficacy was linearly correlated with the prostate size (correlation coefficients, R=0.701, p<0.001). But, enucleation ratio efficacy could eliminate the confounding effect of the prostate size (R=-0.101, p=0.233). The plateau of enucleation ratio efficacy was reached around the twenty-fifth case. Conclusions: Our results demonstrated that the operative learning curve plateau is reached after about 25 cases. We propose that a more appropriate parameter for estimating the operative learning curve is enucleation ratio efficacy, rather than enucleation efficacy.