Safety and Efficacy of Reused Subdural Grid Electrodes in Invasive Monitoring for Drug-Resistant Epilepsy

Subdural grid implantation is essential for invasive intracranial electroencephalogram monitoring in drug-resistant epilepsy (DRE), enabling accurate localization of epileptogenic zones and functional cortical mapping. However, the high cost of single-use electrodes limits access in resource-constrained settings. This study evaluated whether reuse of ethylene oxide (EO)-sterilized subdural grid electrodes is associated with increased postoperative infection risk or inferior seizure outcomes. We conducted a retrospective cohort study of patients with DRE who underwent subdural grid implantation at a tertiary referral center between 2007 and 2025. Patients were categorized into single-use and EO-sterilized reused electrode groups. The primary outcome was postoperative infection within 30 days. Secondary outcomes included Engel seizure classification at 6 months and 1 year and procedure-related complications. A total of 1,148 patients were included (616 single-use and 532 reused). Baseline characteristics were comparable between groups. Multivariate logistic regression demonstrated that reuse of subdural grid electrodes was not independently associated with postoperative infection (adjusted odds ratio [OR]: 0.61; 95% confidence interval [CI]: 0.37–1.01; p = 0.054). Longer operative time was independently associated with infection (adjusted OR: 1.22 per hour; 95% CI: 1.05–1.41; p = 0.010). Seizure outcomes at 6 months and 1 year were similar between groups (p = 0.802 at 1 year). Procedure-related complications did not differ significantly. EO-sterilized reused subdural grid electrodes are safe and effective when strict protocols are followed and may significantly improve access to epilepsy surgery.