Quantification of changes in detrusor function and pressure-flow parameters after radical prostatectomy: relation to postoperative continence status and the impact of intensity of pelvic floor muscle exercises.

Objectives: We aim to quantify changes in detrusor function and pressure-flow parameters after radical retropubic prostatectomy (RRP) and to determine the impact of the level of intensity of pelvic floor muscle exercises (PFME) on these changes. We also tried to identify preoperative urodynamic factors, predictive of postoperative continence status.

Methods: Sixty-six patients were included in the study. An urodynamic examination was performed before surgery and 26 weeks after catheter removal. All patients were instructed in PFME. However the intensity of PFME varied between instructions based on an information folder only (F-PFME) and intensive guidance by a physiotherapist, in addition to the folder (PG-PFME).

Results: In 66 men pre- as well as postoperative urodynamic studies were available for analysis. Overall, Q(max) increased, p(det.Qmax) and the urethral resistance factor URA decreased significantly after surgery. At baseline, detrusor overactivity (DOA) was found in 34% and 5.3% of the men who were still incontinent 6 months postoperatively and those who regained continence, respectively (P = 0.015). Postoperatively, Q(max) was significantly higher (P = 0.04) and URA significantly lower (P = 0.047) in the physiotherapist-guided group. No prognostic standard urodynamic factors for post-RP incontinence (PRPI) were identified.

Conclusion: In univariate analysis, preoperative DOA is associated with a higher risk of remaining incontinent after surgery. However, in multivariate analysis, urodynamic parameters predictive of PRPI could not be identified. Therefore, standard preoperative filling cystometry and pressure-flow studies seem to have no role as preoperative predictors of PRPI in patients with localized prostate cancer. More intensive PFME might have a lowering effect on bladder outflow resistance after RRP.