Complication rates low for vagus nerve stimulation surgeries

Key takeaways:

• Researchers examined 606 vagus nerve stimulation surgeries performed on 437 individuals.
• Mean surgery duration was higher for those with complications compared with those without.

Vagus nerve stimulation surgeries were relatively safe, with complication rates low but differing depending on the type of procedure and presence of complications, researchers reported in Brain and Spine.

“Vagus nerve stimulation is the most frequently used method of neuromodulation in patients with epilepsy,” Jouke van Schooten, BS, a student in the department of neurosurgery, Maastricht University Medical Center, the Netherlands, and colleagues wrote. “Although cardiac side effects such as bradycardia or asystole as a result of VNS are very rare, they can occur.”

As vagus nerve stimulation procedures may result in complications that include surgical site infection, unilateral vocal cord paresis and that previous research shows rates of complications for these procedures may vary, van Schooten and colleagues sought to examine the safety profile of VNS-related surgeries.

Their retrospective cohort study culled data from January 2008 to October 2022 for patient files of those with drug-resistant epilepsy 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 University Medical Center. A total of 606 procedures on 437 individuals were included for analysis, with 306 being primary implantation, 201 were replacements of the pulse generator, 44 resulted in complete removal, 42 were lead replacements and three were incomplete removals. Of these, 67 led to complications (infection was the most common, n = 14); three of those resulted in permanent complications.

The researchers utilized Multiple Imputation for missing data while employing univariable and multivariable logistic regression analysis 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 additionally applied. Complication rate was calculated as a percentage.

The complication rate was 27.3% for complete VNS removal; 21.4% for lead revision; 13.4% after primary implantation and 2.5% for pulse generator replacement, the researchers wrote.

Data additionally showed mean surgery duration was higher (150.71 minutes vs. 123.64 minutes) for those with complications compared with those who did not have complications.

“This study ... demonstrated that VNS removal or lead revision surgery might be related to a higher complication rate compared to generator replacement or primary implantation,” van Schooten and colleagues wrote.