Percutaneous tibial nerve stimulation for the treatment of interstitial cystitis/bladder pain syndrome: a pilot study

Objectives: Interstitial cystitis/bladder pain syndrome (IC/BPS) is a chronic pain condition that requires multimodal management. The American Urologic Association includes sacral neuromodulation in the treatment algorithm for refractory IC/BPS. We sought to determine the rate of overall symptom improvement of IC/BPS symptoms, using validated measures, after treatment with percutaneous tibial nerve stimulation (PTNS), a form of peripheral neuromodulation.

Methods: This was a single-arm, dual-center, pilot study examining a standard PTNS protocol in subjects with IC/BPS. Our primary outcome was subject response of "moderately" or "markedly improved" on the Global Response Assessment (GRA) scale after 12-weekly PTNS sessions. Assuming a 60% response rate, 24 subjects were needed to detect a response rate between 40 and 80% with 95% confidence. Secondary objectives included change in urinary frequency on a 24-h bladder diary, bladder pain as measured by VAS and responses to validated questionnaires for pelvic pain and IC/BPS.

Results: Of 21 subjects enrolled, 16 initiated and 10 completed the PTNS treatment course. The GRA response rate was 40% at week 6 and 30% at week 12. Seventy percent of the cohort had some degree of improvement. There were no adverse events.

Conclusions: While only a minority of subjects with IC/BPS were responders to PTNS per GRA criteria, 70% of the cohort had some degree of improvement. Due to low recruitment and loss to follow-up, we did not achieve our predetermined significance. However, our promising findings add to the limited literature on this subject.