International multi-center study of middle meningeal artery embolization for chronic subdural hematoma in cancer patients: Efficacy, safety, and outcomes in a high-risk population

Background: Middle meningeal artery embolization (MMAE) is a promising treatment for chronic subdural hematoma (cSDH). Cancer patients are at risk for cSDH due to thrombocytopenia. The efficacy of MMAE in this population has not been studied. Methods: We conducted a retrospective analysis of 76 patients who underwent 94 MMAEs for cSDH at 12 tertiary centers across North America and Europe between February 2018 and January 2023. We analyzed patient demographics, clinical profiles, procedural details, and outcomes. The primary outcome was cSDH progression, while secondary outcomes included radiographic resolution, mortality, 90-day functional outcomes, functional improvement, and procedural complications. Results: Radiographic improvement occurred in 88.5% of patients, and technical success was achieved in 96.8%, with comparable rates between the MMAE-only and MMAE + surgery groups. Complications occurred in five patients (5.3%), with no significant difference between groups (6.0% in MMAE vs. 3.7% in MMAE + surgery, p = 0.658). Hemorrhage was reported in four patients (4.3%), and no cases of stroke were recorded. Mortality was 24.5% overall, with a slightly higher rate in the MMAE + surgery group (29.6%) compared to the MMAE-only group (22.4%, p = 0.460). Functional improvement in modified Rankin Scale (mRS) was seen in 15 patients (24.2%), with a significantly greater improvement in the combined group (Δ mRS = 2.625) versus the MMAE-only group (Δ mRS = 0.348, p < 0.001). Conclusions: MMAE is a safe and effective treatment option for managing cSDH in cancer patients. Higher mortality in this population is likely reflective of underlying cancer and comorbidities.