Impact of body mass index on outcomes after robot assisted radical prostatectomy

In this study we evaluated the impact of body mass index (BMI) on operative and perioperative parameters and surgical margin rates, in patients who underwent robotic assisted radical prostatectomy (RARP).We retrospectively reviewed 140 consecutive RARPs performed by the same surgical team. Patients were stratified based on BMI into two categories: Group I: non-obese (91 patients) and Group II: obese (49 patients). Intraoperative parameters evaluated were: total operative time, estimated blood loss (EBL), intraoperative complications, status of nerve sparing and pelvic lymph node dissection. Postoperative parameters evaluated included positive surgical margin rate, pathological Gleason score and pathological stage, final tumor volume, length of stay (LOS), and postoperative complications. The two groups were statistically comparable for age, PSA, Gleason scores and clinical stages. Mean operative time was greater in the obese group at 300.5 min versus 247.3 min in the non-obese group. Mean EBL in obese patients and non-obese patients were 396.2 and 292.8 ml, respectively. Positive surgical margin rate was 26.5% in obese and 13.1% in non-obese patients. Robotic assisted radical prostatectomy in obese patients is a feasible procedure with acceptable perioperative outcomes and complications. In our study, obesity significantly but negatively affected operative and postoperative outcomes. Moreover, obesity was associated with higher grade tumors and higher incidence of positive surgical margins. Consequently, caution is advised in performing RARP in the obese patient in the early part of a learning curve.