Longer preserved urethral length in robot-assisted radical prostatectomy significantly contributes to post-operative urinary continence recovery

Objectives: To assess the relationship between the surgical procedure of robot-assisted radical prostatectomy (RARP) and urinary continence recovery by reviewing the video database. Methods: Video and data about men diagnosed with prostate cancer and underwent RARP were extracted and reviewed. Preserved urethral length (PUL) was semi-quantitatively measured using the lateral width of a 16-Fr urethral balloon catheter while cutting the urethra on a video screen. In addition, by reviewing intraoperative RARP video database, other surgical skill outcomes were also collected. Kaplan-Meier analysis with log-rank test was used to compare the urinary continence recovery rate, stratified by the PUL. Univariate and multivariate analyses were performed using the Cox proportional hazards model, and p-values of <0.05 were considered significant. Results: The number of patients included in this study was 213. In univariate analysis, a PUL of >= 16mm, a body mass index of <23.1 kg/m(2) and a resected prostate volume of <44.3 g were statistically significant factors that influenced urinary continence recovery [hazard ratio (HR) 1.58, p=0.036; HR 0.67, p=0.021; and HR 0.58, p=0.005, respectively]. Those factors also remained statistically significant in the multivariate analysis (HR 1.87, p=0.022; HR 0.54, p=0.001; and HR 0.57, p=0.005, respectively). One year post-operatively, the recovery rate from urinary continence was 79.0% for patients with a PUL of >= 16mm and 66.5% for patients with a PUL of <16mm. Conclusion: These results suggest that patients with longer PUL in RARP have a significantly higher rate of post-operative urinary continence recovery.