Middle Meningeal Artery Embolization: Complete Institutional Report of 294 Non-acute Subdural Hematomas with Outcomes and Risk Factors for Recurrence

Introduction: Middle meningeal artery embolization (MMAe) is a minimally invasive procedure poised to improve outcomes and recurrence rates for non-acute subdural hematoma (NASDH). We evaluated how outcomes for MMAe differ when utilized upfront, prophylactically, or as a salvage modality. Furthermore, we investigated how patient risk factors, such as oncologic history and anticoagulant/antiplatelet (ACAP) medication use, impact MMAe outcomes for NASDH.

Methods: Patients undergoing MMAe for NASDH were prospectively followed from 2016-2021. The primary outcome was NASDH recurrence requiring surgical evacuation, repeat MMAe, or both. Modified Rankin scale (mRS) quantified post-MMAe clinical outcomes. Subgroup analyses stratified outcomes by MMAe indication: upfront, prophylactic, or salvage. Outcomes among oncologic, coagulopathic, and ACAP patients were assessed.

Results: A total of 236 NASDH patients underwent 294 MMAe. Of these, 115 (48.7%), 92 (39.0%), and 29 (12.3%) patients received upfront, prophylactic, and salvage MMAe, respectively. Sixteen (5.4%) patients presented with recurrence requiring repeat intervention, of which 5 (1.7%) underwent craniotomy, 7 (2.4%) received repeat MMAe, and 4 (1.3%) underwent both MMAe and surgical evacuation. Risk of overall SDH recurrence requiring re-intervention did not differ among prophylactic, upfront, and salvage groups (6.5%, 7.0%, 6.9%; P > 0.99). Clinical outcomes did not differ between MMAe indications. Within the prophylactic group, radiographic and clinical outcomes were similar between MMAe paired with twist-drill craniostomy or with craniotomy. Patients with both an oncologic history and concurrent ACAP use less frequently achieved improved clinical status compared with ACAP/coagulopathic history alone, oncologic history alone, or neither (31.4%, 45.9%, 50.0%, 57.3%; P = 0.049).

Conclusion : MMAe curtails NASDH recurrence with similar clinical outcomes when performed prophylactically, upfront, or as salvage treatment. NASDH patients with concurrent oncologic history and ACAP use may be less likely to achieve clinical improvement after MMAe.