Abstract 243: Distal vs Non‐Distal Middle Meningeal Artery Embolization for Subacute‐Chronic Subdural Hematomas

Introduction Subacute‐chronic subdural hematomas have a nearly 25‐30% recurrence rate following appropriate surgical evacuation of the primary hematoma. Recently, middle Meningeal artery (MMA) embolization techniques have demonstrated efficacy in preventing recurrence and has been increasingly adopted as part of mainstay therapy. However, technical considerations are still being established. Methods This is a single center retrospective study from January, 2022 through August, 2024 evaluating patients who received MMA embolization for subacute‐chronic SDH. Patients were excluded if they did not have follow up imaging. Patients were dichotomized into whether they received distal or non‐distal MMA embolization. All patients were treated with Onyx embolization. Embolization was considered distal when Onyx material reached membranous branches. Primary efficacy outcome was defined SDH improvement (reduction or completion resolution of SDH compared to discharge). Results There were 127 patients included in this study with 12 patients excluded for lacking final radiographic outcomes. Therefore, one‐hundred‐fifteen patients were included in the final analysis who were older (75 years) Caucasian (86%) males (78%). Fifty‐five (52%) and sixty (48%) patients received either a distal or non‐distal MMA embolization, respectively. The distally occluded cohort were more likely to be women (31% vs 13% p = 0.02) compared to the non‐distal cohort; otherwise, there were no significant baseline demographic differences between cohorts. Additionally, anticoagulation and antiplatelet usage were similar between cohorts. Patients had final imaging at a median 44 (IQR 26 ‐ 81) days following the procedure. There were equal rates of radiographic improvement between distally and non‐distally occluded MMA embolization techniques (85.5% vs 73.3% p = 0.11). On multivariate analysis controlling for potentially confounding factors, odds of improvement were similar (OR 1.96 95% CI 0.70 ‐ 5.52; p = 0.20). Conclusion Patients had similar rates of radiographic improvement despite choosing distally vs non‐distally occluding the middle meningeal artery. Further prospective research is required to validate our finding.