Vagus nerve stimulation lead removal or replacement: surgical technique, institutional experience, and literature overview

Abstract

Background: With the growing use of vagus nerve stimulation (VNS) as a treatment for refractory epilepsy, there is a growing demand for complete removal or replacement of the VNS system. We evaluate the safety and efficacy of complete removal or replacement of the VNS system and provide an extensive description of our surgical technique.

Methods: We retrospectively reviewed our patient registry for all VNS surgeries performed between January 2007 (the year of our first complete removal) and May 2014. In order to assess patient satisfaction, a written questionnaire was sent to patients or their caregivers. Additionally, we reviewed all literature on this topic.

Results: The VNS system was completely removed in 22 patients and completely replaced in 13 patients. There were no incomplete removals. Revision surgery was complicated by a small laceration of the jugular vein in two patients and by vocal cord paralysis in one patient. Seizure frequency was unaltered or improved after revision surgery. Electrode-related side effects all improved after revision surgery. Twenty-one studies reported a total of 131 patients in whom the VNS system was completely removed. In 95 patients, the system was subsequently replaced. The most frequently reported side effect was vocal cord paresis, which occurred in four patients.

Conclusions: Complete removal or replacement of the VNS system including lead and coils is feasible and safe. Although initial results seem promising, further research and longer follow-up are needed to assess whether lead replacement may affect VNS effectiveness.

Keywords: Epilepsy; Lead; Neuromodulation; Revision; Vagus nerve stimulation.

Fig. 1

Intraoperative image: once the generator is moved out of its pocket, degradation of the silicone coating of the lead is clearly visible. Note the exact point where the lead has left the silicone coating (arrowhead) and the trajectory it has subsequently followed (arrow)

Fig. 2

Intraoperative images before (a, b) and after (c) removal of the helices and finally with the new lead in place (d). A blue vessel loop surrounds the vagus nerve (c, carotid artery; h, helices; j, internal jugular vein)

Fig. 3

Intraoperative image demonstrating short segment atrophy of the vagus nerve as a result of chronic constriction caused by suboptimal position of the helices and/or strain relief loops. Impressions caused by three individual helices (especially the middle one) are clearly visible (arrows). The instrument is holding scar tissue (s) attached to and surrounding the vagus nerve