Upfront middle meningeal artery embolization for treatment of chronic subdural hematomas in patients with or without midline shift

Objectives: There is limited data on upfront middle meningeal artery (MMA) embolization in the context of significant midline shift (MLS) (greater than 5mm) for the treatment of chronic subdural hematomas (cSDH). This study reports the temporal changes following MMA embolization as an upfront treatment of cSDH in patients with or without MLS and either mild, no symptoms or mild and stable neurological deficits. Methods: A retrospective series of patients with a cSDH from a single institution in the United States between 2018-2020 was conducted. Eligible patients were treated with upfront MMA embolization. Results: 27 upfront MMA embolization procedures in 23 patients were included. Twelve patients had MLS of 5 millimeters or more (52%). The median maximal thickness at diagnosis was 18 mm [11-22]. The mean distance of MLS was 5 mm ±4. There were no procedural complications. The overall rescue surgery rate was 15%. A single rescue surgery secondary to an increase in hematoma thickness was required (4%). The temporal changes for both hematoma and MLS showed gradual improvement between 2 weeks and 4 weeks post-procedure. The average time-to-resolution of MLS was 46 days in patients with less than 5 mm MLS and 51 days in those with 5 mm or more. Conclusion: Upfront MMA embolization for cSDH with a thickness up to 25 mm provides adequate symptom relief, stabilization and/or progressive resorption of the cSDH during follow-up in carefully selected asymptomatic or mildly symptomatic patients even in the presence of a MLS greater than 5 mm.