Pilot Study of Percutaneous Posterior Tibial Nerve Stimulation for the Treatment of IC/PBS

Overview

In 2014, the American Urological Association updated it management algorithm for Interstitial Cystitis/Painful Bladder Syndrome (IC/PBS). As the algorithm progresses, interventions become increasingly invasive and morbid. 4th line treatment is sacral neuromodulation (SNM), involving a two stage surgical procedure and permanent device implantation. While the mechanism for decrease in IC/PBS symptoms is unknown, SNM is thought act through central and peripheral mechanisms related to afferent signaling, causing modification of pain and lower urinary tract sensation.¹ Percutaneous posterior tibial nerve stimulation (PTNS) is a method of peripheral neuromodulation targeting the same nerve roots as SNM, but with significantly fewer risks. The purpose of our research is to determine if PTNS is effective in the treatment of IC/PBS. The results of this study will suggest future directions and provide critical information to design studies to determine to what extent and in what situations PTNS may be effective. The investigators will enroll subjects with IC/PBS and urinary frequency/urgency to treatment with 12 weekly treatments of PTNS. The investigators will assess symptoms and lower urinary tract function before, during and after the treatments. At the completion of treatments, subjects will be asked to enroll in post-study follow up monitoring to understand the duration of symptom effect.

The overall objective of this prospective, pilot study is to determine if percutaneous tibial nerve stimulation (PTNS) is an effective treatment for interstitial cystitis/painful bladder syndrome (IC/PBS). Our specific aim is to evaluate how PTNS performs with regards to the reduction of symptoms in subjects with this disorder. The primary outcome variable will be the percentage of subjects to report that they are moderately improved or markedly improved in overall symptoms compared to baseline on a 7-point global response assessment (GRA) scale. The GRA scale involves asking the question, "As compared to when you started the current study, how would you rate your overall symptoms now?". There are 7 possible responses: markedly worse, moderately worse, slightly worse, the same, slightly improved, moderately improved and markedly improved. This scale is the current standard for outcome in studies that are evaluating treatments and interventions for IC/PBS. There will be a number of secondary outcome variables including: changes in a 24 hour voiding diary during the course of the interventions, ratings for bladder pain, urinary urgency and urinary frequency on standardized scales, the score on O'Leary-Sant IC Symptom and Problem Index, scores of validated questionnaires for pelvic floor and general health. The investigators will also collect and report any adverse events. Subjects will be recruited during a routine visit to the University of California, Irvine (UCI) urogynecology division that the patient has scheduled to initiate or continue routine care for their complaints. If the provider feels that the patient may be appropriate for the study and meets the inclusion/exclusion criteria, she will offer to have a study investigator speak with patient at that time or at a later time at the patient's convenience. Once consents are signed, the subject will be provided with the following materials to complete before their first treatment visit: 1. demographic and medical history survey 2. 24 hour voiding diary 3. visual analog scale (VAS) for bladder pain 4. Pelvic Pain and Urgency/Frequency Patient Symptom Scale (PUF Questionnaire) 5. O'Leary-Sant IC Symptom and Problem Index 6. urine pregnancy test (for premenopausal subjects) The PTNS treatment visits will be administered in the standard fashion. This involves the placement of a thin needle (similar to an acupuncture needle) inserted near the posterior ankle. The needle is then connected to an electrode stimulator and the stimulation is adjusted until appropriate response (toe flex or fan) is obtained without patient discomfort. When at the appropriate level, the electrode is stimulated for 30 minutes per treatment session. Study visits will be conducted in the UCI Ob/Gyn clinic with a nurse trained to administer PTNS. These treatments will occur weekly for 12 weeks. (See Section 2.4 for table outlining treatment visits.) At all visits, the nurse will inquire regarding any adverse reactions to treatment and the subject complete a VAS. After completion of the twelfth treatment visit, the subject will be requested to complete the following: 1. 7-point global response assessment (GRA) scale and interval medical history questionnaire 2. 24 hour voiding diary 3. visual analog scale (VAS) for bladder pain 4. Pelvic Pain and Urgency/Frequency Patient Symptom Scale (PUF Questionnaire) 5. O'Leary-Sant IC Symptom and Problem Index These forms will be returned within two weeks and the subject will return to the clinic for a follow up visit with her provider. At this time, depending on their current symptoms and response to the treatment on the GRA scale, the subjects will be offered to continue with PTNS treatments at a maintenance interval or to pursue alternative care outside of the study protocol if no benefit was obtained. If subjects are planning to continue maintenance treatments, they will be asked if they wish to continue with an additional follow up 12-16 weeks after the final treatment visit. The information collected at that time will be as follows: 1. 7-point global response assessment (GRA) scale and interval medical history questionnaire 2. 24 hour voiding diary 3. visual analog scale (VAS) for bladder pain 4. Pelvic Pain and Urgency/Frequency Patient Symptom Scale (PUF Questionnaire) 5. O'Leary-Sant IC Symptom and Problem Index 6. Post-study follow-up survey