COMPLICATION rates of vagus nerve stimulation (VNS) surgeries are generally low, according to a recent study conducted at Maastricht University, the Netherlands. VNS is the most frequently employed neuromodulation treatment for patients with drug-resistant epilepsy, but safety profiles have varied across studies.
In this retrospective cohort study, the authors used data from 437 patients with drug-resistant epilepsy who had undergone a range of VNS surgeries in the Maastricht University Medical Center, including primary implantation of a VNS system (n=306), replacement of the VNS pulse generator (n=201), replacement of the lead (n=42), replacement of both pulse generator and lead (n=3), or complete VNS removal surgery (n=44). The study included a total of 606 VNS-related procedures, conducted between 2008–2022. Univariable and multivariable logistic regression analyses were performed to analyse possible risk factors; in case of a small sample size, an independent samples t-test and Fisher’s exact test, or Pearson’s ꭓ2-test, were used.
According to results, VNS-related surgeries led to 67 complications, three of which resulted in permanent complications. The most common complication was transient hoarseness, followed by surgical site infection. The total surgical complication rate was 11.1%, with a 2.5% complication rate for pulse generator replacement, 13.4% for primary implantation, 21.4% for lead revision, and 27.3% for complete VNS removal. The authors also found longer surgery duration to be a possible risk factor for having a surgical complication after VNS lead revision surgery. No statistically significant results were found when analysing the results of adults and children <18 years of age separately.
The authors concluded that VNS surgery is a relatively safe procedure, with low complication rates, and noted that VNS removal or lead revision surgery might be related to a higher complication rate compared to generator replacement or primary implantation. They added that more research, both on adults and children, will be needed to confirm these results.
