Postoperative membranous urethral length is the single most important surgical factor predicting recovery of postoperative urinary continence.

Purpose: To analyze the potential surgical factors affecting postoperative urinary continence, including postoperative membranous urethral length (MUL), in an era where open radical prostatectomy (ORP) and robot-assisted radical prostatectomy (RARP) coexist.

Methods: Consecutive patients undergoing either ORP or RARP between April 2009 and June 2017 were included in this study. Pericatheter urethrography (PCU) was performed the day of catheter removal to confirm healing of the vesicourethral anastomosis and to measure PCU-MUL. Daily usage of incontinence pad was self-reported by the patient at each post-operative visit through a questionnaire. Univariate and multivariate analyses were performed to identify factors that influenced recovery of continence.

Results: Of the 196 patients included, 121 and 75 patients received ORP and RARP, respectively. The cumulative full continence rates (0 pad/day) at 1 year in the ORP and RARP groups were 87% and 95%, respectively. In the univariate analysis, older age, high preoperative International Prostate Symptom Score (IPSS) irritative symptom domain, ORP, poorer NVB preservation, and shorter PCU-MUL were associated with delayed recovery of full continence. In the multivariate analysis, only older age, high preoperative IPSS irritative symptom domain, and shorter PCU-MUL remained as independent factors significantly associated with delayed recovery of full continence.

Conclusions: Our study highlights the importance of saving the MUL as long as possible in terms of continence recovery. This holds true for ORP even in the era of RARP and surgeons should not simply give up the prospect of early urinary continence in exchange for the patient's choice of ORP instead of RARP.