Middle meningeal artery embolization plus standard care for chronic or non-acute subdural hematoma: an updated systematic review and meta-analysis of 6 randomized controlled trials

Abstract

Chronic subdural hematoma (cSDH) recurs in approximately 10 to 30% of patients following surgical evacuation. Middle-meningeal artery embolization (MMAE) targets the neo-angiogenic blood supply sustaining recurrence. This updated systematic review and meta-analysis pools all available randomized controlled trials (RCTs) of adjunctive MMAE versus standard care for chronic or non-acute subdural hematoma. PubMed, Scopus, Web of Science, and the Cochrane Library were searched from inception through April 2026. Eligible studies were RCTs comparing adjunctive MMAE plus standard care with standard care alone in adults with chronic or nonacute subdural hematoma. The primary outcome was recurrence or residual cSDH. Secondary outcomes included all-cause mortality, serious adverse events, favorable functional outcome (mRS 0â€"2 at 90 days), and major disabling stroke. Random-effects meta-analysis, Bayesian analysis, and trial sequential analysis (TSA) were performed. Evidence certainty was rated using the GRADE framework. PROSPERO [ID: CRD420261446040]. Six RCTs enrolling 2,093 participants were included. MMAE significantly reduced recurrence or residual cSDH (RR≤0.48, 95% CI≤0.30-0.76; I² ≤ 41.3%; moderate certainty). Bayesian analysis confirmed this finding (posterior median RR≤0.48, 95% CrI≤0.32-0.70; 99.9% probability of benefit), and TSA confirmed information sufficiency. No significant differences were observed for all-cause mortality (RR≤0.92, 95% CI≤0.26-3.22; low certainty), serious adverse events (RR 0.90, 95% CI≤0.62â€"1.31), favorable functional outcome (RR≤1.01, 95% CI≤0.96-1.07), or major disabling stroke (RR≤1.18, 95% CI≤0.50-2.78). Adjunctive MMAE reduced cSDH recurrence by approximately half on moderate-certainty evidence. It does not significantly affect mortality, functional outcomes, or safety within current follow-up periods. The unresolved mortality signal requires longer-term investigation.