Proximal Onyx embolization of the middle meningeal artery (POEM) technique for non-acute subdural hematomas: a single-center study of 123 patients using the Scepter dual-lumen balloon microcatheter.

Objective: Non-acute subdural hematomas (NASDHs) often recur or persist, particularly among older patients with comorbidities. Middle meningeal artery embolization (MMAe) has emerged as a promising primary treatment alternative. Dual-lumen balloon microcatheters significantly reduce the risk of reflux, which is a limitation of single-lumen microcatheters. We evaluated the safety and efficacy of the proximal Onyx embolization of the MMA (POEM) technique using the Scepter Mini and Scepter XC balloon microcatheters.

Methods: We conducted a single-center retrospective review of patients with NASDH undergoing Onyx MMAe with the Scepter Mini or Scepter XC microcatheter between July 2020 and January 2025. Demographics, imaging parameters (hematoma thickness, midline shift), procedural details, and clinical and radiographic outcomes were recorded.

Results: 123 patients underwent Scepter balloon-assisted MMAe. Their mean age was 72 years and 67.5% were male. At 6 months, 77.2% achieved ≥50% reduction in hematoma thickness. There were no significant differences in baseline demographics, hematoma characteristics, or surgical intervention rates between patients achieving ≥50% reduction and those with <50%. Five patients (4.1%) experienced recurrence, with average time to recurrence of 76 days. Only three patients (2.4%) required surgical rescue. Safety outcomes included 6.5% all-cause mortality at 180 days, with 1.6% directly related to NASDH. Stroke occurred in 1.6% at 30 days and 4.1% at 180 days.

Conclusion: By minimizing the risk of reflux, balloon-assisted MMAe allows for safe embolization from a more proximal location. The POEM technique shows that proximal embolization with dual-lumen balloon microcatheters treats NASDH effectively, achieving substantial hematoma resolution with low recurrence. Prospective studies comparing POEM with other techniques are warranted to confirm its comparative efficacy.