Middle meningeal artery embolization for chronic subdural hematoma in octogenarians and nonagenarians: an individual patient pooled meta-analysis

Chronic subdural hematoma (cSDH) is a highly common neurosurgical condition with significant burden in the elderly, and patients aged ≥ 80 represent nearly one-third of cases. Middle meningeal artery embolization (MMAE) has emerged as a promising treatment method to reduce hematoma growth and recurrence; however, octogenarians and nonagenarians remain underrepresented in clinical trials. We conducted a systematic review and meta-analysis of individual patient data to evaluate outcomes of MMAE in this high-risk group. We systematically searched PubMed, Scopus, and Web of Science through March 2025 for studies reporting patients aged ≥ 80 years treated with MMAE for cSDH. Individual-level data were extracted and pooled. Clinical, procedural, and radiographic outcomes were summarized. Multivariable mixed-effects logistic regression identified predictors of hematoma resolution and extended hospital stay (LOS ≥ 75th percentile). Twenty-six studies including 86 patients (mean age 83 years; 36% ≥90 years) met inclusion. Most were male (70%) and had comorbidities such as hypertension (57%) and diabetes (21%). MMAE was performed alone in 64% of cases and with surgery in 36%. Transfemoral access was used in 74%, while transradial access (associated with shorter LOS) was underutilized, especially in patients ≥ 90 (3%). Complication and in-hospital mortality rates were low (5.8% and 1.2%, respectively). At discharge, 81% returned home. Complete hematoma resolution occurred in 56%, more likely with adjunctive coiling (aOR 4.01) and less likely with antithrombotic use (aOR 0.12). Extended LOS was associated with age ≥ 90 (aOR 2.1) and general anesthesia (aOR 1.7). MMAE is safe and effective in patients aged ≥ 80. While outcomes are favorable across age groups, transradial access and conscious sedation may reduce hospital stay and anesthesia-related risks in this population. Future trials should prioritize inclusion of this high-risk group to guide age-appropriate, evidence-based care.