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

BACKGROUND AND PURPOSE: Middle meningeal artery embolization (MMAE) is an effective treatment for patients with nonacute subdural hematoma (NASDH), 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 patients with NASDH treated with MMAE. MATERIALS AND METHODS: We conducted a retrospective cohort study using the 2016-2022 Nationwide Readmissions Database. Patients with NASDH were stratified into stand-alone MMAE versus combined MMAE+surgery groups. Propensity score matching 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 postdischarge. RESULTS: Among 3213 patients with NASDH (1669 MMAE-only; 1544 MMAE+surgery), 1108 patients per group remained after propensity score matching. Overall, surgery was not associated with lower treatment failure (5.3% versus 7.5%; hazard ratio = 0.67 [95% CI, 0.37-1.21]; P = .19). A significant interaction between surgery and ECI was observed (P-interaction = .002). Surgery reduced treatment failure in patients with low comorbidity burden (ECI < 5; hazard ratio = 0.29 [95% CI, 0.11-0.78]; P = .01). For patients with medium (ECI = 5-14, n = 996) or high (ECI ≥ 15, n = 589) comorbidity burden, surgery was not associated with different outcomes (P = .56 and .43, respectively). CONCLUSIONS: For neurologically stable patients with NASDH who underwent MMAE, baseline comorbidity burden significantly blunted the marginal benefit of surgery. Additional surgical evacuation was not associated with different rates of treatment failure for most patients with NASDH with medium-to-high comorbidity burdens.