Coil only middle meningeal artery embolization versus particles or liquid embolic agents for chronic subdural hematoma

BACKGROUND: Middle meningeal artery embolization (MMAE) for chronic subdural hematoma (cSDH) with particles or liquid embolic agents has been shown to be effective, but can carry a theoretical risk of off-target embolization via dangerous collaterals and anastomoses. Primary coiling has been suggested as a safer alternative, particularly for patients with dangerous anastomoses. This study aims to evaluate the safety and efficacy of coil only for cSDH patients compared with liquid or particle embolic agents. METHODS: We performed a retrospective review of cSDH patients who underwent MMAE between 2023 and 2025. Patients were stratified by coil only versus liquid/particle embolization strategy. The primary outcome was rate of surgical rescue; secondary outcomes included the amount and rate of hematoma resorption. Subgroup analysis was performed among those with identified dangerous anastomoses. RESULTS: A total of 168 patients were included; 88 (52.4%) underwent coil only embolization. Coil only patients had significantly lower rates of altered mental status (P=0.010), diabetes (P=0.015), and thrombocytopenia (P<0.001), but higher rates of anticoagulant use (P=0.017). During study follow-up (median duration 52 and 74 days for coil only and liquid/particle, respectively; P=0.23), coil only was not associated with different rates of surgical rescue (5.7% vs 2.5%, P=0.52), percentage hematoma resorption (P=0.82), or percentage hematoma resorption rate (P=0.86). There was no difference in these outcomes among the 65 (39%) patients with angiographic evidence of vascular anastomosis or dangerous collaterals (P>0.05). CONCLUSIONS: The results of the study indicate that coil only MMAE may be a safe and equally effective alternative to particle or liquid embolics for patients with cSDH.