MIDDLE MENINGEAL ARTERY EMBOLIZATION FOR CHRONIC SUBDURAL HEMATOMA AFTER RANDOMIZED TRIALS: MEMBRANE-TARGETED THERAPY, RECURRENCE-RISK STRATIFICATION, AND INTEGRATED NEUROSURGICAL–ENDOVASCULAR CARE

Abstract

Background. Chronic subdural hematoma is increasingly understood as an angiogenic inflammatory disease of the dural border-cell compartment rather than a passive residual collection. Surgical drainage relieves mass effect rapidly but does not directly interrupt vascularized membrane biology, creating a rationale for middle meningeal artery embolization.

Materials and methods. Randomized trials, consensus statements, prospective cohorts, anatomical studies, and technical investigations published through July 2026 were synthesized. Evidence was organized according to urgency, hematoma phenotype, recurrence risk, surgical strategy, embolic agent, distal penetration, dangerous anastomoses, antithrombotic requirements, radiological resolution, and functional outcome.

Results. EMBOLISE reduced recurrence or progression requiring reoperation after surgery from 11.3% to 4.1%. STEM reduced a broader 180-day treatment-failure composite from 36% to 16% across surgical and nonsurgical strata. MAGIC-MT and EMPROTECT did not meet their primary efficacy endpoints, demonstrating that endpoint definition, population, timing, and embolic strategy materially affect trial results. MEMBRANE reported a reduction in six-month residual or recurrent hematoma or surgery from 22.1% to 11.6% with n-butyl cyanoacrylate. MMA embolization acts gradually and should not replace urgent decompression in patients with severe mass effect or neurological deterioration.

Conclusion. The strongest evidence supports adjunctive embolization in selected nonemergent patients at risk of recurrence. The proposed framework integrates membrane activity, expansion risk, morphology, brain re-expansion, recurrence predictors, arterial anatomy, neurological urgency, embolic strategy, and follow-up to distinguish patients requiring immediate drainage, combined treatment, or embolization-centered management.