Standalone middle meningeal artery embolization versus Burr-hole surgery in nonacute subdural hematomas and selection strategy based on hematoma volume: A MAGIC-MT trial secondary analysis

Background and objectives Middle meningeal artery embolization (MMAE) has emerged as an alternative technique with minimally invasive nature in nonacute subdural hematomas (NASDH). However, whether MMAE alone can replace burr-hole surgery (BHS) remains unclear. Methods This exploratory secondary study used data from the MAGIC-MT randomized controlled trial to compare standalone MMAE and BHS. The primary outcomes were symptomatic recurrence and progression of hematomas. Overlap weighting (OW) was used to balance baseline variables between groups. Propensity score matching (PSM) was used as sensitivity analysis. Results A total of 291 BHS and 77 MMAE patients were included. After balancing baseline features, the incidence of primary outcomes in MMAE was significantly higher than that in BHS (OW: 10.9% vs 3.2%, P=0.021; PSM: 10.7% vs 0%, P=0.027). Hematoma volume was an independent risk factor to predict the primary outcomes (adjusted OR, 1.02 (1.01–1.03), P=0.001). In the subgroup with hematoma volume <98 mL, both MMAE and BHS demonstrated low primary outcomes rate (OW: 1.8% vs 0%, P=0.713; PSM: 2.9% vs 0%, p>0.999). Moreover, patients benefited from standalone MMAE with shorter length of hospital stay (OW: P=0.011, PSM: P=0.001). However, in the subgroup with hematoma volume >98 mL, standalone MMAE showed a significantly higher rate of primary outcomes than BHS (OW: 23.5% vs 8.2%, P=0.049; PSM: 23.8% vs 0%, P=0.021). Conclusion Given the advantage of its minimally invasive nature and low primary outcome rates when hematoma volume is <98 mL, standalone MMAE was an alternative strategy to replace BHS in this population. When hematoma volume is >98 mL, standalone MMAE cannot be routinely recommended to replace BHS.