Evaluation and management of malfunctioning sacral neuromodulator

ObjectivesTo describe a strategy for revising the malfunctioning InterStim device and to provide an algorithm for evaluation and management.MethodsWe retrospectively reviewed 82 patients who had undergone InterStim placement. Ten patients (eight women and two men) experienced complications and subsequently underwent revision of their device between October 2001 and October 2003. Five patients had originally received a permanent implant after a successful percutaneous test stimulation trial, and five had undergone a test stimulation using the tined lead. Indications for revision included gradual onset of recurrent voiding dysfunction (n = 2), lead migration (n = 5), generator malfunction (n = 1), generator site pain and infection (n = 1), and genital/rectal pain with stimulation (sensory discomfort; n = 1).ResultsOf the 10 patients who underwent revision, 7 experienced complete resolution of their problem. Eight patients had lead site changes and two had generator replacements. No intraoperative or postoperative complications occurred in the revision cases.ConclusionsIn our experience, 70% of patients who undergo revision of the malfunctioning InterStim can expect success. In this study, no difference in success appeared to be related to the original cause of malfunction. In the management of malfunctioning sacral neuromodulators, we recommend an attempt at revision before permanent explantation.