Abstract 293: Identifying risk factors for post‐operative seizure after chronic subdural hematoma treatment with craniotomy, burr hole evacuation or middle meningeal artery embolization.

Objective Post‐operative seizures can occur in 2.6% to 23% of patients with chronic subdural hematomas (cSDH). Hematoma size, midline shift, worse clinical status at admission, and craniotomy with membranectomy have been described as risk factors for its development; however, the impact of middle meningeal artery embolization (MMAe) remains unexplored. This retrospective study aims to determine post‐operative seizure rates in cSDH patients treated with MMAe and compare them with those undergoing craniotomy and burr hole evacuation. Methods A bi‐institutional retrospective review of 592 cSDH treated surgically and endovascularly from 2017 to 2021 was conducted. Patient, hematoma, and procedural characteristics were compared among interventions using Fisher exact tests, t‐tests, and ANOVA. Multivariate logistic regression was employed to compare the relationship of post‐operative seizures with the type of treatment, adjusting for sex, age, subdural SDH thickness, midline shift, pre‐operative GCS score, and prophylactic AED use. Secondary outcomes evaluated included complications, additional drainage, and length of hospitalization. Results Post‐operative seizure rates were 3.1% for burr hole evacuation, 2.6% for burr hole evacuation with MMAe, 15.3% for craniotomy, 11.1% for craniotomy with MMAe, and 6.7% for MMAe alone. Multivariate logistic regression revealed lower seizure rates in patients undergoing burr hole evacuation with or without MMAe compared to those with MMAe alone (p=0.007, OR 0.18, 95% CI 0.05‐0.62). Craniotomy with or without subsequent MMAe had a higher risk of post‐operative seizure compared to burr hole drainage with or without MMAe (p=0.0002, OR 5.66, 95% CI 2.28‐14.04). Overall post‐operative complications were lower in MMAe alone compared to burr hole drainage alone (P=0.01, OR 0.35, 95% CI 0.15‐0.79). Conclusion Burr hole evacuation demonstrated the lowest post‐operative seizure rates in cSDH patients, followed by MMAe alone and then craniotomy, and this association was significant after controlling for confounders.