Learning curve in robot-assisted partial nephrectomy: comparison between an expert surgeon and a team in training in single-center experiences

INTRODUCTION: An important issue in robotic surgery is the training of urologists and the learning curve to perform a robot-assisted partial nephrectomy (RAPN), especially for those procedures that require vascular clamping. MATERIAL AND METHODS: We retrospectively enrolled 333 patients, undergoing RAPN in the period between 01/2014 and 12/2020. Surgical complexity, surgery duration, perioperative complications, and clamping were evaluated for each patient. Comparisons were made between an experienced surgeon and 3 urologists with initial experience in robotic surgery. RESULTS: Total number of RAPN was 333, of wich 172 were performed by the chief and 142 by the team. Analyzing the data, after an initial training in robotic surgery, it’s possible to perform surgery of medium complexity (RENAL score 6-7) after 15 procedures performed in total independence. To proceed to high complexity tumors (RENAL score 8-9) with possible vascular clamping and warm ischemia time <25 minutes at least 25 completely independent procedures are required. There were no significant differences in the comparisons regarding the duration of the procedures (p = 0.19), complications (p = 0.44) and positive margins (p = 0.96). CONCLUSIONS: Robotic training for complex procedures, with low intra and postoperative complication rates, acceptable positive margin rates and sustainable cost-effective durations, requires a minimum number of medium complexity procedures, which in our study we have identified as 25 procedures, considering the initial ability in simple procedures of our 3 surgeons in training.