Purpose: Stimulation of the sacral nerves is a commonly used treatment for frequency, urgency, urge incontinence, retention and other types of voiding dysfunction. Minimally invasive placement of a percutaneous permanent quadripolar tined lead into the sacral foramen has been described. No lead migration has been reported. We report on our experience with lead migration and the subsequent failure of InterStim in a large cohort of patients with a focus on possible diagnostic and salvage techniques.
Materials and methods: Between February 2002 and April 2005 tined lead electrodes were implanted in the S3 foramen in 235 patients using the InterStim system. Patients with a good response during the testing phase (greater than 50% improvement) underwent placement of an implantable pulse generator. Position was confirmed by radiographic evaluation intraoperatively. Sacral radiographs were obtained at the first postoperative visit, after IPG placement and whenever there was a change in symptomatic response.
Results: There were 5 patients (2.1%) in whom treatment failed after a successful trial of stimulation due to lead migration. This was seen as early as 3 weeks and as late as 8 months. Migration of the lead occurred between first and second stage implantation in 1 of the 5 cases, and occurred after the second stage in 4 of 5. Anterior migration was noted in 4 patients and posterior migration was noted in 1.
Conclusions: Lead migration after placement of the tined lead can occur and thus sacral radiographs should be routinely used. This complication can be easily resolved without significant morbidity to the patient.