Transcutaneous mechanical nerve stimulation using perineal vibration: a novel method for the treatment of female stress urinary incontinence.

PURPOSE We defined basic guidelines for transcutaneous mechanical nerve stimulation in modifying pelvic floor responses in women and determined the efficacy of transcutaneous mechanical nerve stimulation in treating stress urinary incontinence. MATERIALS AND METHODS Perineal and clitoral transcutaneous mechanical nerve stimulation was performed in healthy volunteers while measuring changes in peak urethral pressure to determine optimal vibration amplitude and site of stimulation. Perineal transcutaneous mechanical nerve stimulation was then performed weekly for 6 weeks in a cohort of women with stress urinary incontinence (33). Reduction in incontinence episodes and pad use on voiding diary were compared from baseline to 6 weeks. Global efficacy was determined at 6 weeks and 3 months after the completion of the program. RESULTS In healthy subjects a vibration amplitude of 2.0 mm resulted in the highest urethral pressure increase. Although the increase with perineal transcutaneous mechanical nerve stimulation was lower than that seen with clitoral stimulation (80 vs 115 cm H(2)O), perineal transcutaneous mechanical nerve stimulation was more acceptable to the patient and resulted in a better subjective response. Urethral pressure increases with transcutaneous mechanical nerve stimulation at either site were greater than with voluntary contraction (60 cm H(2)O). After 6 weeks of transcutaneous mechanical nerve stimulation in the subjects with stress urinary incontinence, there was a significant reduction in daily incontinence episodes (2.6 +/- 1.1 vs 0.5 +/- 1.1, paired t test p <0.001) and pad use (3.5 +/- 0.9 vs 0.6 +/- 1.3, paired t test p <0.001). At 6 weeks the cure rate (no incontinence episodes) was 73%, with durability through 3 months with 67% still reporting persistent resolution. CONCLUSIONS Perineal transcutaneous mechanical nerve stimulation has promise as a noninvasive and well tolerated method of treating stress urinary incontinence.