Real-World Safety Profile of Middle Meningeal Artery Embolization for Chronic Subdural Hematoma: a Multinational Multicenter Study

BACKGROUND: Middle meningeal artery embolization (MMAE) has emerged as a treatment for chronic subdural hematoma (cSDH), but comprehensive real-world safety data remain limited. METHODS: We performed a multicenter retrospective analysis of 1781 consecutive patients undergoing MMAE for cSDH (2019-2025). The primary outcome was any procedure-related complication within 30 days. Inverse probability of treatment weighting (IPTW) assessed the association between technical success and complications, adjusting for demographic, clinical, and procedural confounders. RESULTS: Mean age was 72.8 ± 12.4 years; 68.1% were male. The 30-day complication rate was 5.1% (91/1781; 95% CI, 4.1-6.2). In-hospital mortality was 2.9% (47/1625). Technical success was achieved in 97.5% (1505/1543). Among documented complications, thromboembolic events were most common (37.2%; 32/86), followed by hemorrhagic complications (23.8%; 20/84) and access-site hematoma (10.4%; 8/77). Among patients with classifiable symptom status, 80.6% of complications were symptomatic, yielding an overall symptomatic complication rate of 3.0%. Neurological deterioration occurred in 27.1% (248/915). Among 1552 patients with documented surgical approach, complication rates were similar between surgery plus embolization (4.9%; 34/690) and embolization alone (5.2%; 45/860; OR, 0.94; 95% CI, 0.59-1.48; p = 0.79). After IPTW adjustment, technical success was associated with an 86% reduction in complication odds (OR, 0.14; 95% CI, 0.05-0.40; p < 0.001). CONCLUSIONS: In this large multicenter cohort, MMAE was associated with a 5.1% complication rate. Technical success was the strongest protective factor. Embolization with or without surgery showed equivalent safety profiles.