Comparative effectiveness of standalone middle meningeal artery embolization versus surgical evacuation in noncritical patients with nonacute subdural hematomas

Neurosurg Focus 59(4):E8, 2025

This retrospective propensity score–matched cohort study compares standalone middle meningeal artery embolization (sMMAE) with standard surgical evacuation for nonacute subdural hematomas (NASDH) in noncritical patients treated from 2017–2024. Primary outcome was reintervention for recurrence; secondary outcomes included hospital length of stay (LOS), new neurological deficits, and adverse events.

After matching 85 patients per group, reintervention rates did not differ significantly (IRR 1.38, p=0.41). sMMAE was associated with shorter median LOS (4 vs 6 days, p=0.003) and fewer noncardiorespiratory medical adverse events, suggesting sMMAE may be a less-invasive option in selected patients while larger trials are needed.

• Standalone Middle Meningeal Artery Embolization (sMMAE) vs. Surgery: sMMAE for nonacute subdural hematoma (NASDH) showed no significant difference in reintervention rates due to hematoma recurrence compared to surgical evacuation (incidence rate ratio [IRR] 1.38, p = 0.41).

• Hospital Length of Stay: Patients treated with sMMAE had a significantly shorter hospital stay (median 4 days) compared to those who underwent surgical evacuation (median 6 days, p = 0.003).

• Adverse Events: sMMAE was associated with a lower risk of other medical (non-neurological, non-cardiorespiratory) adverse events (1.1% vs 15.2%; relative risk [RR] 0.07, p = 0.013), with no significant differences in new neurological deficits or cardiorespiratory/neurological adverse events between groups.

• Patient Selection: The findings apply to noncritical NASDH patients (midline shift < 10 mm, no coma) who are eligible for either intervention; results do not extend to patients with larger or rapidly deteriorating hematomas.

• Propensity Score Matching: Groups were balanced for key confounders (age, sex, comorbidities, hematoma characteristics) using propensity score matching, enhancing comparability of outcomes.

• Mortality: Mortality rates during follow-up were similar between groups and deaths were unrelated to the primary outcome of recurrence.

• Study Limitations: Limitations include retrospective design, moderate sample size, incomplete long-term clinical outcome data, and potential residual confounding by indication or procedural heterogeneity.

• Clinical Implication: sMMAE may offer a less invasive alternative to surgery with shorter hospitalization and fewer medical complications for selected NASDH patients, but larger studies are needed to confirm noninferiority and guide patient selection.