Feasibility of outpatient middle meningeal artery embolization for chronic subdural hematoma

Middle meningeal artery embolization (MMAe) has emerged as a safe and efficacious treatment for chronic subdural hematoma (cSDH). Performing this procedure on an outpatient basis has the opportunity to accelerate recovery and provide economic advantages. However, data supporting such protocols remain limited. This study aims to substantiate the feasibility of outpatient MMAe by describing its success at our institution.

A single-center retrospective cohort analysis of all patients undergoing outpatient MMAe for cSDH was conducted between August 2023 and March 2025. Primary outcomes included procedural complication rates, postprocedural emergency department (ED) return rates, and 30-day readmission rates. Secondary outcomes included hematoma recurrence or expansion, degree of symptom resolution, and radiographic outcomes.

64 patients were included in the analysis, with a median age of 76 years (interquartile range [IQR]: 68-80). The majority of embolizations (77%) served as primary treatment. The median hematoma depth was 11 mm (IQR 7-15), with bilateral hematomas present in 42% of cases. No intra-procedural complications occurred; however, two patients suffered minor postprocedural complications. The 30-day readmission rate was 5% (n = 3), with no readmissions within 48 h. 17% of patients (n = 11) returned to the ED - the median time from embolization to ED presentation was 12 days (IQR 4-17 days). Among 52 patients (81%) with long-term follow-up, 4% suffered hematoma recurrence requiring surgical drainage, 58% achieved complete resolution of symptoms, and 29% showed improvement in symptoms.

The study suggests that outpatient MMAe can be both safe and feasible for select patients with cSDH.