Impact of preoperative pelvic floor muscle strength and endurance on urinary continence after radical prostatectomy: a sub-analysis of a randomized clinical trial.

Introduction: To assess the impact of preoperative pelvic floor muscle (PFM) strength on urinary incontinence (UI) after radical prostatectomy (RP). Material and methods: A total of 127 men who underwent surgical treatment for clinically localized prostate cancer in a tertiary university hospital were included in a sub-analysis. PFM strength (cmH2O) and endurance (s) were measured using a perineometer on the day before and at 1, 3, and 6 months after surgery. UI volume was measured using an 8-hour pad test. The primary outcome was continence, defined as 0-5 grams of urine during the 8-hour pad test at 6 months post-RP. The association between baseline PFM strength and continence was analyzed using Spearman's correlation coefficient, receiver-operating characteristic analysis, and logistic regression analysis. Results: At 6 months post-RP, 45 of 127 (35.4%) men were continent. UI showed a strong negative (r = -0.7; p <0.001) association with preoperative PFM strength and a medium negative (r = -0.55; p <0.001) association with PFM endurance. PFM strength (odds ratio [OR] = 1.16, p <0.0001), PFM endurance (OR 1.6, p <0.0001), and preoperative prostate-specific antigen (OR = 0.87, p = 0.03) were the most significant predictors of continence in the univariate regression analysis. In the multivariate analysis, only PFM strength remained a significant predictor (OR = 1.13, p <0.001) of UI. The thresholds for PFM endurance and strength were 9.6 seconds and 98.9 cmH2O, respectively. Conclusions: Preoperative PFM strength and endurance demonstrated significant associations with postoperative UI. Objectively measured preoperative PFM conditions could help identify patients at increased risk of UI after RP.