Historical collection · First published Nov 20, 2024; added to EM Weekly Oct 27, 2026. This retrospective summary may be superseded by later evidence or guidance.
← All articlesAdjunctive Middle Meningeal Artery Embolization for Subdural Hematoma
Summary
EMBOLISE was a prospective multicenter randomized trial of 400 patients with symptomatic subacute or chronic subdural hematoma requiring surgical evacuation. Adjunctive middle meningeal artery embolization reduced hematoma recurrence or progression leading to repeat surgery within 90 days from 11.3% with surgery alone to 4.1% (RR 0.36, 95% CI 0.11-0.80; P=0.008). Neurologic functional deterioration was 11.9% versus 9.8%; 90-day mortality was 5.1% versus 3.0%.
Why it matters
For ED patients with symptomatic nonacute subdural hematoma who are admitted for neurosurgical evacuation, this trial supports discussing adjunctive MMA embolization with neurosurgery or neurointerventional teams as a strategy to reduce repeat surgery. It does not make embolization an ED procedure or establish benefit for every chronic subdural hematoma phenotype.
Study at a glance
- Design
- Randomized trial
- Population
- Adults with symptomatic subacute or chronic subdural hematoma with an indication for surgical evacuation.
- Sample size
- 400
- Intervention
- Middle meningeal artery embolization plus surgical evacuation.
- Comparator
- Surgical evacuation alone.
- Primary endpoint
- Hematoma recurrence or progression leading to repeat surgery within 90 days after index treatment.
Main findings
- Repeat surgery for hematoma recurrence or progression occurred in 4.1% with embolization plus surgery versus 11.3% with surgery alone (RR 0.36, 95% CI 0.11-0.80; P=0.008).
- Neurologic functional deterioration at 90 days was 11.9% versus 9.8% (risk difference 2.1 percentage points, 95% CI -4.8 to 8.9).
- Ninety-day mortality was 5.1% versus 3.0%.
- Serious embolization-related adverse events occurred in 2.0%, including two disabling strokes.
Limitations
Surgery occurred before randomization in 34% of participants. Serious embolization-related adverse events occurred in 2.0%, including two disabling strokes, and the trial was funded by Medtronic; later MMA embolization trials produced heterogeneous efficacy results, so patient selection remains important.
Read the primary source
Full text: Abstract available; full text paywalled.
Original sourcePMID: 39565988
Material reviewed: abstract.
Source retrieved Oct 27, 2026. NEJM publisher metadata verifies publication online on 2024-11-20; PubMed verifies DOI 10.1056/NEJMoa2313472 and PMID 39565988. The publisher abstract and PubMed abstract were reviewed; the full article was not reviewed end-to-end. Subsequent randomized MMA embolization evidence was heterogeneous, including MAGIC-MT, and later society guidance supports selected use while patient selection remains debated. No retraction was identified in the targeted cross-check.
Corrections & review history
No corrections recorded. Human review: not yet human-reviewed.