Enucleated Weight/Enucleation Time, Is It Appropriate for Estimating Enucleation Skills for Holmium Laser Enucleation of the Prostate? A Consideration of Energy Consumption

PURPOSE: To date, the parameters for evaluating enucleation efficiency have only considered enucleation time, although operators simultaneously consume both time and energy during holmium laser enucleation of the prostate. This study was undertaken to find a better way of assessing enucleation skills, considering both enucleation time and consumed energy. MATERIALS AND METHODS: One hundred (n=100) consecutive patients who underwent holmium laser enucleation of the prostate from April 2012 to April 2014 by a single surgeon were enrolled. Ten groups of 10 consecutive cases were used to analyze the parameters of enucleation efficiency. RESULTS: The mean enucleation time, consumed energy, and enucleated weight were 41.3±19.2 minutes, 66.2±36.0 kJ, and 26.6±21.8 g, respectively. Concerning learning curves, like enucleation time-efficacy (=enucleated weight/enucleation time), enucleation energy-efficacy (=enucleated weight/consumed energy) also had an increasing tendency. Enucleation ratio efficacy (=enucleated weight/transitional zone volume/enucleation time) plateaued after 30 cases. However, enucleation time-energy-efficacy (=enucleated weight/enucleation time/consumed energy) continued to increase after 30 cases and plateaued at 61 to 70 cases. Furthermore, one-way analysis of variance showed that group means for enucleation time-energy-efficacy (F=3.560, p=0.001) were significantly different, but that those of enucleation ratio efficacy (F=1.931, p=0.057) were not. CONCLUSIONS: When both time and energy were considered, enucleation skills continued to improve even after 30 cases and plateaued at 61 to 70 cases. Therefore, we propose that enucleation time-energy-efficacy should be used as a more appropriate parameter than enucleation ratio efficacy for evaluating enucleation skills.