Introduction: The factors that contribute to continence following robot-assisted radical prostatectomy (RARP) are currently being investigated. The purpose of this study is to determine the relationship of the bladder neck location on postoperative cystogram to subsequent continence rates following RARP.
Patients and methods: A retrospective review of 611 consecutive RARP patients identified 215 patients with a postoperative cystogram. A ratio was created by measuring the distance from the superior edge of the pubic symphysis to the bladder neck and dividing it by the total pubic symphysis height, termed the bladder neck to pubic symphysis (BNPS) ratio. Odds ratios with 95% confidence intervals (CI) were calculated for the relationship between incontinence and BNPS tertile categories.
Results: At 3-month follow-up, continent patients had a mean BNPS ratio of 0.39 (95% CI 0.35, 0.43), while incontinent patients had a mean BNPS ratio of 0.49 (95% CI 0.42, 0.56; p=0.01). At 12 months, the mean BNPS ratio was 0.40 (95% CI 0.37, 0.44) for continent patients, whereas incontinent patients had a mean BNPS ratio of 0.60 (95% CI 0.43, 0.77; p=0.001). When analyzed as tertile groups, the corresponding incontinence rates at 12 months were 2.8%, 2.8%, and 19.4% for the lowest, middle, and highest BNPS tertiles, respectively.
Conclusions: Postprostatectomy bladder neck location defined by the BNPS ratio on cystogram correlates with continence rates and may predict patients at risk for prolonged incontinence. Efforts designed to preserve support of the bladder neck and sphincteric complex in relation to the pubic symphysis may improve both early and late continence.