Anticoagulation Resumption After Middle Meningeal Artery Embolization for Subdural Hematoma

Introduction/Purpose The optimal timing of anticoagulation (AC) resumption following middle meningeal artery embolization (MMAE) for subdural hematoma (SDH) remains uncertain. While MMAE has been shown to reduce recurrence, evidence guiding AC management after the procedure is limited. This study evaluated clinical outcomes associated with AC resumption following MMAE. Materials and Methods We performed a retrospective multicenter cohort study of adults undergoing technically successful MMAE for symptomatic SDH. Patients were stratified by whether AC therapy was resumed within 30 days after the procedure. Demographic, clinical, radiographic, and procedural variables were collected. Inverse probability of treatment weighting was applied to balance baseline characteristics. The primary endpoint was SDH recurrence requiring reintervention within 90 days. Secondary outcomes included all‐cause and in‐hospital mortality, functional status at discharge, neurological deterioration, seizures, hospital length of stay, procedural complications, and composite outcomes. Prespecified subgroup analyses were conducted by age, prior AC use, and embolization laterality. Results A total of 634 patients were included, with 356 resuming AC and 278 not resuming. After weighting, recurrence occurred in 2.6% of the resumption group versus 5.2% of the non‐resumption group (risk ratio [RR] 0.50; 95% CI, 0.22‐1.15; P = .079). All‐cause mortality was lower with AC resumption (8.0% vs 15.3%; RR 0.52; 95% CI, 0.32‐0.85; P = .034), as was in‐hospital mortality (0.5% vs 4.2%; RR 0.11; 95% CI, 0.03‐0.44; P = .013). Good functional outcome (mRS 0‐2) was achieved in 70.7% versus 63.9% (RR 1.11; 95% CI, 0.98‐1.25; P = .161). The composite endpoint of death or recurrence was significantly reduced (9.3% vs 17.8%; RR 0.53; 95% CI, 0.35‐0.80; P = .007). Subgroup analysis showed the strongest benefits in patients ≥75 years (RR 0.29; P = .033), prior AC users (RR 0.31; P = .055), and unilateral embolization cases (RR 0.14; P = .019). Safety outcomes, including seizures, repeat surgery, and procedural complications, were similar or lower with AC resumption. Conclusion AC resumption after MMAE was associated with significantly lower mortality and no increased risk of recurrence. The benefit was most pronounced in elderly patients and those undergoing unilateral embolization. These findings suggest MMAE may provide a safer context for earlier AC reinstitution. Prospective trials are needed to establish definitive timing recommendations. image FIGURE 1. IPTW‐Adjusted Rates of Primary and Secondary Outcomes by Anticoagulation Resumption Status. Bar chart comparing rates of SDH recurrence requiring intervention, MMAE procedural complications, and functional outcomes (mRS 0‐2) between patients who resumed anticoagulation (diagonal stripes) and those who did not (white bars). Brackets show p‐values and absolute risk differences. image FIGURE 2. Risk Ratios for Primary, Secondary, and Exploratory Endpoints. Forest plot displaying risk ratios with 95% confidence intervals for all analyzed endpoints, stratified by endpoint category. The plot uses IPTW‐adjusted estimates to compare outcomes between patients who resumed anticoagulation versus those who did not.