Stand-alone Middle Meningeal Artery Embolization May Obviate Surgery among Patients with Nonacute Subdural Hematoma with Moderate-to-High Comorbidity Burden

ABSTRACT BACKGROUND AND PURPOSE: Middle meningeal artery embolization (MMAE) is an effective treatment for non-acute subdural hematoma (NASDH) patients, and it is increasingly being adopted into routine clinical practice as standard of care. This study aims to determine whether additional surgery is necessary to prevent treatment failure for NASDH patients treated with MMAE. MATERIALS AND METHODS: We conducted a retrospective cohort study using the 2016–2022 Nationwide Readmissions Database. NASDH patients were stratified into standalone MMAE vs. combined MMAE+surgery groups. Propensity score matching (PSM) accounted for presenting symptoms and discharge functional status. The Elixhauser Comorbidity Index (ECI) quantified comorbidity burden. The primary outcome was treatment failure, defined as NASDH-related death, readmission, or surgical evacuation within 180 days post-discharge. RESULTS: Among 3,213 NASDH patients (1,669 MMAE-only; 1,544 MMAE+surgery), 1,108 patients per group remained after PSM. Overall, surgery was not associated with lower treatment failure (5.3% vs 7.5%; HR 0.67 [95% CI, 0.37–1.21]; p=0.19). A significant interaction between surgery and ECI was observed (p-interaction=0.002). Surgery reduced treatment failure in patients with low comorbidity burden (ECI