What factors affect the operative time of robot-assisted laparoscopic radical prostatectomy?

Robot-assisted radical prostatectomy (RARP) has gained prominence since the da Vinci surgical system was introduced in 2000. RARP has now become a standard procedure for treating cases with localized prostate cancer. However, no study has examined its surgical time by accurately measuring the pelvic visceral fat (PVF) volume. This study aimed to investigate the factors associated with prolonged console time and surgical difficulty by RARP surgeons.

This study included 405 patients who underwent RARP between 2014 and 2019 at our institution. Given that the anatomical characteristics were considered to affect RARP, PVF and working space (WS) were estimated preoperatively by computed tomography using a 3D image analysis system. Univariate and multivariate logistic regression analyses were performed to identify the factors prolonging console time, such as body mass index (BMI), prostate volume, previous abdominal surgery, nerve-sparing procedure, PVF, and WS. We also investigated whether post-operative complications were associated with any of these factors.

Larger PVF (p = 0.028, odds ratio (OR) 1.43), smaller WS (p < 0.001, OR 2.48), and the nerve-sparing procedure (p = 0.037, OR 1.61) were statistically significant factors associated with prolonged console time. Furthermore, higher BMI (p = 0.013, OR 1.49) and smaller pelvic width (p < 0.001, OR 2.63) were the alternative and more practical factors associated with prolonged console time. The post-operative anastomotic leakage occurrence rate increased with the number of risk factors, while post-operative complications did not change even in high-risk cases.

PVF and WS are significant factors associated with prolonged console time in RARP cases. However, BMI can be as useful as PVF, since BMI significantly correlated with PVF. Additionally, pelvic width (PW) can be an alternative to WS, since PW correlated with WS. This study demonstrated that preoperative BMI and PW might predict the surgical risk and identify suitable RARP cases for novice surgeons.