Complications and troubleshooting of two-stage sacral neuromodulation therapy: a single-institution experience

With the increasing use of sacral neuromodulation therapy, urologists are faced with postimplantation challenges. The purpose of this study was to identify these events and their causes and management in our large single-institution experience.

From July 2002 to September 2004, all patients who underwent sacral neuromodulation therapy for refractory bladder conditions were identified. Their medical records were retrospectively evaluated for history, operative intervention, and programming visits. Events after implantation of the implantable pulse generator (IPG) unit were noted. The evaluation, troubleshooting, management, and resolution of events at the last follow-up visit were extracted.

A total of 214 patients underwent sacral neuromodulation therapy at our institution. The mean patient age was 53.5 +/- 15.4 years. Of the 214 patients, 161 underwent IPG implantation during a mean follow-up period of 16 months (range 5 to 30). The second-stage explantation and revision rate was 10.5% and 16.1%, respectively. The indications for explantation were infection (8 of 17) and failure to maintain a response (9 of 17). Revisions were done for decreases in response with abnormal (12 of 26) or normal (5 of 26) impedance measurements, IPG site discomfort (4 of 26), draining sinus at the IPG site (4 of 26), and lead migration (1 of 26). Equalization of impedance measurements was the most commonly observed impedance abnormality. These were managed by drying fluid from the connection in 4 patients and lead change in the rest.

After IPG implantation, a decline in response may occur. Although some were explanted, most were revised, with most of the revisions functional on follow-up. Familiarity with impedance evaluation and development of algorithms for postimplant management are essential for troubleshooting and maintenance of the device.