Short-term Efficacy and Mechanism of Electrical Pudendal Nerve Stimulation Versus Pelvic Floor Muscle Training Plus Transanal Electrical Stimulation in Treating Post-radical Prostatectomy Urinary Incontinence

To assess the short-term efficacy of electrical pudendal nerve stimulation (EPNS) versus pelvic floor muscle training (PFMT) plus transanal electrical stimulation (TES) for the early treatment of post-radical prostatectomy urinary incontinence (PRPUI) and explore its mechanism of action.A parallel designed randomized controlled trial was conducted at a research institute and a university hospital. Ninety-six PRPUI patients were allocated to EPNS group (64 cases) and PFMT+TES group (32 cases) and treated by EPNS and biofeedback-assisted PFMT plus TES, 3 times a week for 8 weeks, respectively. Outcome measurements were improvement rate, scores of the International Consultation on Incontinence Questionnaire-Urinary Incontinence Short Form (ICIQ-UI SF) and the number of used diapers.After 24 treatments, the efficacy rate of 68.7% in EPNS group was significantly higher than that of 34.4% in PFMT+TES group (P=0.005). The ICIQ-UI SF score, and urine leakage amount score, diaper score, symptom and quality of life improved significantly in both groups and showed Therapy x Treatment interaction, and the above scores in EPNS group were significantly lower than these in PFMT+TES group. Perineal ultrasonographic recordings showed that PFM movement amplitude during EPNS (≥1- <3 mm) was similar to that during PFMT, however, PFM movement EMG amplitude was significantly higher during EPNS than during PFMT (P <0.001).EPNS is more effective than PFMT+TES in short-term (8 weeks) treatments of early urinary incontinence after radical prostatectomy. Its mechanism of action is that EPNS can excite the pudendal nerve and simulate PFMT.