Predictors of surgical difficulty according to surgical proficiency in robot-assisted radical prostatectomy.

Background: Robot-assisted radical prostatectomy (RARP) is a standard treatment for localized prostate cancer. We previously reported that a large amount of pelvic visceral fat and a small working space, as measured by three-dimensional image analysis, were significantly associated with prolonged console time in RARP, and these factors could be alternatives to the more clinically practical body mass index (BMI) and pelvic width (PW), respectively. Herein, we further investigated whether surgical proficiency affected surgical difficulty as measured by console time.

Methods: Medical records of 413 patients who underwent RARP between 2014 and 2020 at our institution were reviewed. Surgeons who had experience with over and under 100 cases were defined as "experienced" and "non-experienced," respectively. Multivariate logistic regression analyses were performed to identify factors that prolonged console time.

Results: The median console times for RARP by experienced and non-experienced surgeons were 87.5 and 149.0 min, respectively; a difficult case was defined as one requiring time greater than the median. Among inexperienced surgeons, higher BMI (p < 0.001, odds ratio: 1.89) and smaller PW (p = 0.001, odds ratio: 1.86) were significant factors that increased console time; the complication rate was increased in patients with these factors. However, these factors did not significantly affect the console time or complication rate among experienced surgeons.

Conclusion: This study demonstrates that experienced surgeons may be able to overcome obesity- and small workspace-related surgical difficulties. The current analysis may provide useful information regarding unpredictable surgical risks and identify suitable cases for novices.