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Introduction: Vagus nerve stimulation (VNS) is the most frequently used neuromodulation treatment for Drug-Resistant Epilepsy (DRE) patients. Complications of VNS surgery include surgical site infection and unilateral vocal cord paresis. Complication rates vary across studies. Research question: What is the safety profile of VNS related surgeries? Materials and methods: Retrospective cohort study using patient files of DRE-patients who had undergone primary implantation of a VNS-system, replacement of the VNS pulse generator, replacement of the lead, replacement of both pulse generator and lead, or VNS removal surgery in the Maastricht UMC+. Multiple Imputation was used for missing data. Univariable and multivariable logistic regression analysis were performed to analyze possible risk factors, in case of a small sample size, an independent-samples t-test and Fisher's exact test or Pearson's X2-test were used. The complication rate was calculated as percentage. Results: This study included a total of 606 VNS surgical procedures, leading to 67 complications of which 3 permanent complications. Complication rate after primary implantation was 13.4%; 2,5% for pulse generator replacement; 21.4% for lead revision and 27.3% for complete VNS removal. No statistically significant results were found when analyzing the results of adults and children <18 years separately. Discussion and conclusion: Complication rates of VNS-related surgeries in our own institutional series are low and comparable to previously reported series. VNS surgery is a relatively safe procedure. The complication rate differs per type of surgery and mean surgery duration was longer for patients with complications after lead revision surgery compared to patients without complications.
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INTRODUCTION: Epilepsy is one of the most common chronic neurological disorders. Antiseizure medication (ASM) is the first choice of treatment, however, 30% of epilepsy patients are drug-resistant. For these patients, neuromodulation can be an option, especially when epilepsy surgery is not possible or did not lead to seizure freedom. Epilepsy is associated with reduced quality of life (QoL), which heavily depends on seizure control.The most recent Cochrane reviews have shown that vagus nerve stimulation and deep brain stimulation of the anterior nucleus of the thalamus, lead to a responder rate OR of, respectively, 1.93 and 1.20. The question arises if neuromodulation for drug-resistant epilepsy (DRE) will be more cost-effective than sole treatment with ASM. The current study aims to determine the change in QoL after neuromodulation. Secondarily, we will aim to study the cost-effectiveness of these treatments. METHODS AND ANALYSIS: This prospective cohort study aims at including 100 patients aged 16 or above who will be referred for neuromodulation, from January 2021 to January 2026. After informed consent, QoL and other relevant parameters will be assessed at baseline, 6 months, 1, 2 and 5 years after surgery. Data on seizure frequency will be derived from patient charts. We expect that DRE patients will report better QoL after neuromodulation. Even if they would still report seizures, the treatment can be seen as useful. This is especially true when patients can participate in society again to a greater extent than before treatment. ETHICS AND DISSEMINATION: The board of directors of participating centres all gave permission for this study to commence. The medical ethics committees decided that this study does not fall under the Medical Research Involving Human Subjects Act (WMO). The findings of this study will be presented at (inter)national conferences and in peer-reviewed journals. TRIAL REGISTRATION NUMBER: NL9033.
