Percutaneous tibial nerve stimulation for the long-term treatment of overactive bladder: 3-year results of the STEP study.

PURPOSE

We report the long-term efficacy and safety of percutaneous tibial nerve stimulation with the Urgent® PC Neuromodulation System for overactive bladder after 3 years of therapy.

MATERIALS AND METHODS

Fifty participants in the randomized, double-blind SUmiT (Sham Effectiveness in Treatment of Overactive Bladder Symptoms) Trial who met the primary effectiveness end point after 12 weekly percutaneous tibial nerve stimulation treatments were enrolled in this prospective study to assess long-term outcomes with percutaneous tibial nerve stimulation. STEP (Sustained Therapeutic Effects of Percutaneous Tibial Nerve Stimulation) Study patients were prescribed a fixed schedule 14-week tapering protocol followed by a personal treatment plan aimed at sustaining overactive bladder symptom improvement. Overactive bladder and quality of life questionnaires were completed every 3 months and 3-day voiding diaries were completed every 6 months.

RESULTS

A total of 29 patients completed the 36-month protocol and received a median of 1.1 treatments per month after a 14-week treatment tapering protocol. A Bayesian model estimated that 77% (95% CI 64-90) of patients maintained moderate or marked improvement in overactive bladder symptoms at 3 years. Compared to baseline, median voids per day decreased from 12.0 (IQR 10.3-13.7) to 8.7 (IQR 7.3-11.3), nighttime voids per night decreased from 2.7 (IQR 1.7-3.3) to 1.7 (IQR 1.0-2.7) and urge incontinence episodes per day decreased from 3.3 (IQR 0.7-6.0) to 0.3 (IQR 0.0-1.0) (all p <0.0001). All quality of life parameters remained markedly improved from baseline through 3 years (all p <0.0001). One patient experienced 2 mild treatment related adverse events of bleeding at the needle site during followup.

CONCLUSIONS

Most STEP participants with an initial positive response to 12 weekly percutaneous tibial nerve stimulation treatments safely sustained overactive bladder symptom improvement to 3 years with an average of 1 treatment per month.