Use of peripheral neuromodulation of the S3 region for treatment of detrusor overactivity: a urodynamic-based study.

OBJECTIVES: To determine the efficacy of peripheral neuromodulation of the S3 region in patients with urgency-frequency syndrome due to an overactive bladder.

METHODS: Fifteen patients (11 women and 4 men) with urgency-frequency syndrome, as documented by a voiding chart, were diagnosed with overactive bladder. Pelvic pain was assessed by a visual analogue scale (VAS). Full urodynamic workup was performed before and after 12 peripheral stimulations with a 9-V monopolar generator, the so-called Stoller Afferent Nerve Stimulator (SANS). Follow-up was for a mean (SD) of 10.9 (4 to 15) months.

RESULTS: Reduction in pain was achieved in all patients, with a decrease in VAS from a mean (SD) of 7.6 (5 to 10) to 3.1 (1 to 7) (P = 0.00049). Seven patients (46.7%) had a complete response and were considered cured, 3 (20.0%) showed significant improvement, and 5 (33.3%) were classified as nonresponders. Urodynamic evidence of bladder instability, evident in all patients before treatment, was eliminated in 76.9% of patients. In all patients, mean (SD) total bladder capacity increased significantly from 197 (35 to 349) to 252 (78 to 384) mL (P = 0.00795), mean (SD) volume at first bladder sensation from 95 (16 to 174) to 133 (32 to 214) mL (P = 0.00166), and mean (SD) bladder volume at normal desire to void from 133 (27 to 217) to 188 (47 to 296) mL (P = 0.00232). In the responding group, the mean (SD) total numbers of voids was reduced from 16.1 (9 to 24) times during the day and 4.4 (2 to 6) times during the night to 8.3 (6 to 10) and 1.4 (1 to 2) times (P = 0.002539), respectively. No complications from treatment were observed.

CONCLUSIONS: Peripheral neuromodulation of the S3 region can successfully treat patients with urgency-frequency syndrome due to an overactive bladder.