REMOVAL AND REVISION OF VNS-THERAPY SYSTEM ELECTRODES; SURGICAL TECHNIQUE AND CLINICAL OUTCOME

　

REMOVAL AND REVISION OF VNS-THERAPY SYSTEM ELECTRODES; SURGICAL TECHNIQUE AND CLINICAL OUTCOME

HE van der Aa, MD, Ph.D., Department of neurosurgery, Medisch Spectrum Twente, Haaksbergerstraat 55, 7513 ER Enschede, Netherlands

JJM Vangeneugden, MD, Ph.D., Department of neurosurgery, AZ ST Maarten, Duffel, Belgium

HPJ Buschman, Ph.D., Twente Institute for Neuromodulation, Medisch Spectrum Twente, Netherlands

BACKGROUND: Vagal nerve stimulation (VNS) for the management of intractable seizure disorders and chronic depression is increasingly being used. Concern was raised about the possibility of revision or removal of the VNS-Therapy helical stimulating electrode in case of a technical failure or once treatment is considered no longer desired or proven ineffective. Because the electrodes are wrapped around the nerve, there is the potential for nerve injury during their removal. We report our experience with removal and revision of the VNS-Therapy electrodes.

METHODS: We performed removal and/or revision of VNS-electrodes in 4 patients who received long-term VNS-therapy for drug-resistant epilepsy.

RESULTS: All patients (2 males and 2 females), were adults at the onset of VNS-Therapy. The mean duration of electrode implantation was 2.8 years (range 0.5-4.0 years).

In all patients, the old electrodes were removed completely from the nerve. One patient had the system removed because of severe VNS-therapy related side-effects combined with insufficient clinical benefit. Two patients had the system removed because of the need for MRI of the head, of whom one underwent subsequent radiosurgery. In the fourth patient a new electrode was placed as a result of lead failure. No adverse events occurred intraoperatively or postoperatively.

CONCLUSIONS: Vagal nerve stimulation remains a viable option for improving seizure control in difficult to treat patients with epilepsy or improving mood in patients with chronic refractory depression. Device removal or revision as a result of insufficient clinical response and/or surgical complications such as hardware failure can be performed with success by an experienced surgeon.

http://www.ifess.org/INS_WSSFN_2005/WSSFN/ABSTRACT/177.pdf