The aim of the study is to evaluate the safety and effectiveness of primary first-line middle meningeal artery embolization (MMAE) for chronic subdural hematoma (CSDH) in a selective group of patients, with follow-up imaging and assessment of volumetric outcomes.

We performed a single-center, prospective interventional study involving 50 consecutive adults with CSDH who were initially treated with MMAE. Participants had symptomatic CSDH with minimal mass effect or ataxia/weakness, imaging showing chronic collections with neo-membranes, and medical issues that made open surgery risky. All patients underwent MMAE using polyvinyl alcohol particles through transfemoral microcatheterization of the MMA. We measured hematoma volume using Medtronics Stealth S6 and S7 system (in mL) on non-contrast head CT at baseline and at 1, 4, 8, 12, and 16 weeks. We classified outcomes at final follow-up as CR: virtually no residual hematoma) or near-total resolution (near-total resolution: minimal residual volume). Clinical neurological status was also recorded.

Fifty patients (mean age 63.7 years, 66% male) were treated. The average presenting hematoma volume was approximately 70.4 mL (range 20 − 128 mL). Follow-up imaging showed a steady decrease in volume after embolization: mean volume dropped from 70.4 mL at baseline to 47.3 mL at 4 weeks and 30.4 mL at 8 weeks (p < 0.001). At final follow-up (median 12 weeks), 28 of 50 treated hemispheres (56%) showed complete resolution, and 22 (44%) had near-total resolution. Follow-up CT images demonstrate progressive hematoma clearance over time. No patient required additional surgery, and there were no procedure-related complications. Functional outcomes were positive, with most patients asymptomatic or improved by 3 months. Embolization successfully ceased hematoma progression in all cases.

Primary MMA embolization is a safe, minimally invasive, and effective treatment for chronic subdural hematoma in selected patients. It achieved high rates of hematoma resolution without the need for further surgery in this prospective series. Larger controlled trials are needed to confirm these findings and to establish the optimal indications for MMAE as a primary therapy.

Article published online:
15 April 2026

© 2026. The Author(s). This is an open access article published by Thieme under the terms of the Creative Commons Attribution License, permitting unrestricted use, distribution, and reproduction so long as the original work is properly cited. (https://creativecommons.org/licenses/by/4.0/)

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