Effects of surface and intravaginal electrical stimulation in the treatment of women with stress urinary incontinence: randomized controlled trial.

Objective: To evaluate the effects of surface electrical stimulation (SES) and to compare them with the effects of the intravaginal electrical stimulation (IVES) in women with stress urinary incontinence (SUI).

Study Design: This randomized controlled study included 48 women aged over 50 years, who complained of SUI evaluated according to two structured questions of King's Health Questionnaire (KHQ) and who had not previously undergone physical therapy for SUI. The calculation of the sample size estimated a sample of 45 volunteers with a significance level of 5% and statistical power of 90%. The women were randomized to: Surface Electrical Stimulation Group (SESG) (n=15), Intravaginal Electrical Stimulation Group (IVESG) (n=15) and Control Group (CG) (n=15). Subjects in the intervention groups were treated with the same parameters of electrical stimulation for 12 sessions. The SESG had four silicone electrodes fixed in the suprapubic and ischial tuberosity regions. The IVES group used an intravaginal electrode. The CG did not receive any treatment during the corresponding time. They were evaluated before and after treatment by a physical therapist who was blind to group allocation. The primary outcomes were urinary leakage, pressure and strength of pelvic floor muscle (PFM) contraction. The secondary outcome was quality of life (QOL) evaluated by KHQ. Forty-five women completed the study and were included in the analysis. Statistical analysis was performed using the Wilcoxon test for intragroup analysis and Kruskal-Wallis and Mann-Whitney tests for intergroup analysis (p<0.05).

Results: There was significant improvement in urinary loss and pressure of contraction in the SESG and IVESG. PFM strength increased only in the IVESG. Intergroup analysis found differences after the treatment in: urinary leakage between the SESG and CG (p<0.001) and the IVESG and CG (p<0.001). Regarding QOL, there was significant reduction in the incontinence impact, limitations of daily activities, physical limitation, emotion, sleep and disposition and severity domains in the SESG (all p<0.02) and IVESG (all p<0.04) after the treatments.

Conclusion: SES and IVES are important treatments to improve the SUI. Both improved the QOL, urinary leakage, and strength and pressure of PFM contraction.