Timing of Adjunctive Middle Meningeal Artery Embolization Relative to Surgical Evacuation for Chronic and Subacute Subdural Hematomas

BACKGROUND AND PURPOSE: Recent randomized trials have suggested that middle meningeal artery embolization (MMAE) is an effective treatment for preventing the recurrence of subacute and chronic subdural hematoma. Thus, MMAE is increasingly being adopted as the standard of care worldwide, and it is projected to become the most common neurointerventional procedure by 2029. While MMAE is an effective surgical adjunct, the optimal timing of MMAE relative to surgical evacuation remains unclear. This study evaluated whether the timing of MMAE influences clinical and health care use outcomes. MATERIALS AND METHODS: We conducted a retrospective cohort study using the 2019–2022 Nationwide Readmissions Database. Nonelectively hospitalized patients with subacute and chronic subdural hematoma who received both surgical evacuation and MMAE were included. Patients were stratified into 3 groups based on MMAE timing: before, same-day (concurrent), or after-surgery. Outcomes included discharge disposition, in-hospital complications and mortality, 180-day treatment failure and surgical rescue, hospitalization cost, and length of stay (LOS). Multivariable adjustments were made for baseline characteristics that were different among study groups (P, .10). RESULTS: Of 1518 patients, 325 (21.4%) received concurrent MMAE1surgery, 149 (9.8%) MMAE-first, and 1043 (68.7%) surgery-first. There were no significant differences in discharge disposition, in-hospital complications, mortality, or 180-day outcomes across timing groups (all, P . .05). However, concurrent MMAE1surgery was associated with shorter LOS (median, 5 days) compared with MMAE-first (8 days, adjusted P, .001) and surgery-first (8 days, adjusted P, .001). Moreover, concurrent MMAE1surgery was associated with significantly lower hospitalization costs (median, $42,147) compared with MMAE-first ($53,536; adjusted P ¼ .014) and surgery-first (median, 53,941 USD; adjusted P, .001). CONCLUSIONS: Clinical outcomes were comparable across timing strategies for MMAE as an adjunct to surgery. However, concurrent MMAE1surgery was associated with significantly reduced LOS and hospitalization costs, suggesting logistical and economic advantages for same-day treatment.