Retzius-sparing versus standard robot-assisted radical prostatectomy: a prospective randomized comparison on immediate continence rates.

Background: Post-prostatectomy urinary incontinence is an adverse event leading to significant distress. Our aim was to evaluate immediate urinary continence (UC) recovery in a single-surgeon prospective randomized comparative study between the traditional robot-assisted laparoscopic radical prostatectomy (TR-RALP) and the Retzius-sparing RALP (RS-RALP), for the treatment of the clinically localized prostate cancer (PCa).

Methods: 102 consecutive PCa patients were prospectively randomized to TR-RALP (57) or RS-RALP (45). Postoperative continence was defined as patient-reported absence of leakage or use of 0 pads/day. The immediate continence rate and 95% confidence interval (CI 95%) were calculated for each treatment. Univariable and multivariate logistic regressions were used to assess predictors of immediate continence following RALP. Continence rates from 1 to 6 months were calculated by Kaplan-Meier curves; log-rank test was used for the curve comparison. Two analyses were performed, considering a per-protocol (PP) population regarding all randomized patients that received nerve-sparing RALP and an Intention-To-Treat (ITT) population regarding all randomized patients that received RALP.

Results: In the PP analysis, the rates of immediate continence were 12/40 (30%) (CI 95% 17-47%) for the TR-RALP and 20/39 (51.3%) (CI 95% 35-68%) for the RS-RALP (p = 0.05). In the ITT analysis, the corresponding rates were 12/57 (21%) (CI 95% 11-34%) for the TR-RALP and 23/45 (51%) (CI 95% 36-66%) for the RS-RALP (p = 0.001). Median time to continence was 21 days for the TR-RALP and 1 day for RS-RALP, respectively (p = 0.02). The relative Kaplan-Meier curves regarding continence resulted statistically different when compared with the log rank test (p = 0.02). In the multivariate analysis, lower age and the Retzius-sparing approach were significantly associated to earlier continence recovery.

Conclusions: The Retzius-sparing approach significantly reduces time to continence following RALP. Further studies are required to confirm the reproducibility of our results and investigate the role of the RS-RALP as an additional "protective" factor for postoperative continence in the elderly population.