Assessing the value of a pelvic drain for urinary leak after robotic radical prostatectomy

Aim: The value of post-operative pelvic drain placement after robot-assisted radical prostatectomy (RARP) for the purpose of diagnosing post-operative complications is undetermined. The aim of this study was to assess the yield of pelvic drain outputs in predicting post-operative early-onset urinary leaks from a vesicourethral anastomosis. Methods: We conducted a retrospective analysis of 204 consecutive patients who underwent RARP in our institution between 2018 and 2022. The daily outputs of the drain and the urinary catheter were measured, and patients with early-onset anastomotic urinary leak were compared with those who were free of any leak. The association between post-operative drain output and the presence of urinary leak was investigated by regression analyses. Results: Post-operative early-onset leak was present in six patients (3.4%) whose baseline characteristics were not different from those of patients with no leak. The median pelvic drain output on post-operative day 1 (D-POD1) was 80 mL (interquartile range [IQR] 51–150 mL) and 122 mL (IQR 62–200 mL) on D-POD2. The median D-POD1 of patients with a leak was significantly higher than those without one (250 mL vs 80 mL, respectively; P <.001). The threshold to predict an anastomotic urinary leak was 227 mL on D-POD1 (area under the curve 0.88; P <.001), and an association between D-POD1 >227 mL and the presence of urinary leak (odds ratio 35; P <.001) was found. Conclusions: Pelvic drain output on POD1 can predict early-onset urinary leak. Given the relatively low rate of this complication via a robotic approach, however, we consider that, unless otherwise indicated, the routine placement of a pelvic drain may be safely avoided.