Middle Meningeal Artery Embolization for Nonacute Subdural Hematoma: A Meta-Analysis of Large Randomized Controlled Trials

BACKGROUND: Middle meningeal artery embolization (MMAE) has emerged as a novel treatment for non-acute subdural hematoma (SDH), particularly for reducing the risk of SDH recurrence. Recently, 5 randomized controlled trials (RCTs) of MMAE as an adjunct to conventional management (surgical or observant) have concluded their investigation and reported their outcomes. PURPOSE: Our goal was to synthesize trial results to provide more definitive guidance on the role of MMAE in the management of non-acute SDH. DATA SOURCES: The MEDLINE database from inception up to November 23, 2024 was used. English-language clinical articles reporting large randomized controlled trials (n ¼ 100 or more) investigating the efficacy and safety of MMAE for patients with non-acute subdural hematoma were identified. STUDY SELECTION: Five trials were identified–EMBOLISE, STEM, MAGIC-MT, EMPROTECT, and MEMBRANE. DATA ANALYSIS: The primary efficacy end point was SDH treatment failure (broadly defined as SDH recurrence or requirement of surgical rescue) within 3 to 6 months. Safety end points include death and stroke. DATA SYNTHESIS: There was significant heterogeneity in terms of patient populations as well as reported outcomes. Overall, MMAE was associated with significantly lower odds of SDH treatment failure (OR 0.51 [95% CI 0.39–0.67], P, .001), with minimal inter study heterogeneity. Compared with conventional management, MMAE was not significantly associated with different odds of death (OR 1.03 [95% CI 0.36–2.99], P ¼ .95) or stroke (OR 1.10 [95% CI 0.36–3.39], P ¼ .86). LIMITATIONS: Our meta-analysis is limited by selection bias and high heterogeneity in study design and reported outcomes. CONCLUSIONS: This study provides high-level evidence that, for patients with non-acute SDH, MMAE is a safe and effective adjunct to conventional management for preventing treatment failure.