Intravesical prostatic protrusion may affect early postoperative continence undergoing robot-assisted radical prostatectomy

BACKGROUND: In this study, we investigated the effect of preoperative prostate morphology, especially intravesical prostatic protrusion (IPP), on continence after robot-assisted radical prostatectomy (RARP). METHODS: Retrospective analysis was applied to patients who underwent RARP between October 2010 and July 2014. The following parameters were assessed in all patients: age, body mass index (BMI), prostate-specific antigen, magnetic resonance imaging and pressure-flow studies findings. The impact of preoperative and intraoperative factors on postoperative urinary incontinence (UI) was assessed using multivariate logistic regression analysis. To evaluate the effects of IPP, the patients were divided into groups according to the IPP length: Group 1, < 5 mm and Group 2, ≥ 5 mm. The International Prostate Symptom Score (IPSS), Overactive Bladder Symptom Score, Quality of Life index and the number of pads used were assessed. RESULTS: A total of 119 patients were eligible for this study. Multivariate analyses showed that IPP (odds ratio (OR) 1.14, 95% confidence interval (CI) 1.02–1.28, p < 0.05) and nerve-sparing (NS) (OR 0.23, 95% CI 0.18–0.61, p < 0.01) were significant factors related to UI in the first month after RARP. Twelve months after RARP, multivariate analyses revealed that only NS is a factor related to postoperative UI (OR 0.23, 95% CI 0.18–0.61, p < 0.01). The comparison of Groups 1 and 2 indicated significant differences in age (p < 0.01), prostate volume (p < 0.01), total IPSS and voiding symptom score (p < 0.05), compliance (p < 0.01), and detrusor pressure at maximum flow (p < 0.01). Group 1 had a higher continence rate (38.0%) than Group 2 (20.8%) in the first month after RARP (p < 0.05), but the difference was no longer significant from the third month after RARP. The total IPSS and voiding symptom scores were significantly different between the two groups before RARP, however, the significant difference disappeared from the first month after RARP. CONCLUSIONS: The data suggest that IPP affects early postoperative UI. Although NS was strongly involved in UI in the early and later stages after RARP, IPP had no effect on UI in the later stages.