Abstract: PD54-11
Sources of Funding: Colter Foundation Grant at the University of Pittsburgh

Introduction

A non-invasive and convenient overactive bladder (OAB) treatment with no major adverse events would be ideal. We previously showed that stimulation of afferent nerves in the foot for 3 hours daily with transcutaneous adhesive pad electrodes (FootStim) decreased urgency urinary incontinence (UUI) and urgency frequency in women with refractory OAB. Yet, the ideal stimulation duration remains unknown. In this study, we sought to define the ideal stimulation duration in women with refractory OAB who underwent FootStim for either 30 minutes or 3 hours daily for 1 week._x000D_

Methods

Women with refractory OAB were recruited onto the study. All these patients with UUI stopped OAB drug therapy 2 weeks prior to study initiation. A 3-week voiding diary was obtained, and FootStim was applied during week 2. The patients underwent FootStim for either 30 minutes or 3 hours daily. Baseline voiding parameters were measured during week 1, and the post-stimulation effect was measured during week 3. Adhesive pad electrodes were attached to the bottom of the foot and connected to a transcutaneous electrical nerve stimulator. Stimulation parameters included pulse frequency of 5 Hz, pulse width of 0.2 ms, and intensity of 2-4 times the minimal stimulation necessary to induce a toe twitch. Responder was defined as having a statistically significant improvement in 1 or more OAB symptoms.

Results

33 women completed the study, of which 19 underwent stimulation for 3 hours and 14 underwent stimulation for 30 minutes. The response rates were 16/19 (84%) in the 3 hour group and 10/14 (71%) in the 30 minute group. In the 3 hour group incontinence frequency decreased from 3.7 to 2.8 leaks/day (p=0.04) and urgency frequency decreased from 7.6 to 6.6 episodes/day (p=0.03). Daytime voiding frequency (n=8) and nocturia (n=7) decreased in the 3 hour group. In contrast, only incontinence frequency decreased in the 30 minute group, and this dropped from 5.3 to 4.3 leaks/day (p=0.03). In the 30 minute group urgency frequency improved in 2, nocturia improved in 1, and daytime urinary frequency improved in none. FootStim effects persisted in both groups for 4 days after treatment ended. There were no adverse events in either group.

Conclusions

FootStim for either 30 minutes or 3 hours daily decreased UUI frequency in women with refractory OAB; however, FootStim for 3 hours better improved the other OAB symptoms. Our results support further testing of FootStim to determine long-term efficacy and stimulation schedule.

Funding

Colter Foundation Grant at the University of Pittsburgh