285 POSTOPERATIVE CYSTOGRAM FINDINGS USED TO PREDICT PERSISTENT INCONTINENCE FOLLOWING ROBOT-ASSISTED RADICAL PROSTATECTOMY

INTRODUCTION AND OBJECTIVES: Incontinence is a dreaded complication following robot-assisted radical prostatectomy (RARP). The ability to predict a slow return of continence would allow appropriate expectations to be set and also allow early, targeted therapy with Kegel exercises, physiotherapy, and biofeedback. The purpose of this study is to determine whether a low bladder neck position on postoperative cystogram predicts subsequent incontinence at 3 and 12 months. METHODS: A retrospective review of 611 consecutive RARP patients at a single institution from 2005 to 2011 was performed. In 263 patients, a postoperative cystogram allowed the anatomic position of the bladder neck in relation to the symphysis to be calculated using a ratio called the Bladder Neck to Pubic Symphysis ratio (BNPS). 215 patients had complete 3 and 12 month continence data. The BNPS ratio was defined as the distance from the superior aspect of the pubic symphysis to the bladder neck on antero-posterior cystogram divided by the total pubic symphysis height, and was reported as a percentage. Continence was assessed by the number of pads used in a 24-hour period at 3 and 12-months follow-up. Patients using no pads or 1 pad for protection were considered continent. Continent and incontinent groups were compared with Student's t-test and Chi-square analyses. RESULTS: Mean patient age was 62 years and body mass index 29 kg/m2. At 3 months follow-up, continent patients had a higher position of the bladder neck with a mean BNPS ratio of 39.2% versus 48.7% in incontinent patients (p = 0.01). Similarly, at 12 months, continent patients had a higher position of the bladder neck, mean BNPS 40.3% versus 60.3% in incontinent patients (p = 0.001). At 3 months, patients with a BNPS ratio greater than 50% were significantly more likely to be incontinent (OR 2.23). Similarly, patients at 12 months with a BNPS ratio of greater than 40% were more likely to be incontinent (OR 8.24). Upon subanalysis, when posterior rhabdosphincter reconstruction was performed, there was a 95.8% continence rate at 12 months compared to 86.0% when reconstruction was not performed (p=0.019). Furthermore, when the pubovesical fascia was preserved, BNPS was significantly decreased from 53.9% to 31.5% (p = 0.01). CONCLUSIONS: Post-prostatectomy bladder neck location defined by the BNPS ratio correlates with incontinence and may predict patients at risk for prolonged incontinence. Furthermore, this study suggests that efforts designed to preserve or reestablish support of the bladder neck may improve both early and late continence following RARP.