To assess the clinical efficacy of middle meningeal artery (MMA) embolization as a treatment for chronic subdural hematoma (cSDH) and to analyze the factors that contribute to the success of cSDH treatment using MMA embolization alone.

We retrospectively included 33 patients with cSDH who underwent MMA embolization at Neurosurgery Department of Beijing Hospital from July 2021 to November 2023. Demographic, clinical, and radiographic data were collected. Surgical outcomes, perioperative complications, and clinical and radiographic follow-up outcomes were also collected. Patients were categorized into two groups: those who received MMA embolization alone and those who also underwent concurrent burr hole drainage. Inter-group differences were compared, by univariate analysis (the Fisher exact, t-tests, or Mann-Whitney U tests) and multivariate Logistic regression analysis was performed to identify the factors influencing the success of treatment with MMA embolization alone.

Thirty-three patients with 43 sides affected by cSDH were included. MMA embolization alone was successful in 22 patients, while 11 patients also received concurrent burr-hole drainage. Technical success was achieved in all patients, with a complication rate of 3.0% (1/33) represented by one case of facial palsy. Among the 29 patients who had a minimum of 2 weeks imaging follow-up, the median imaging follow-up duration was 92.0 (52.5, 161.0) days, and 26 cases (89.7%) showed a reduction in maximum hematoma thickness ≥50% compared to preoperative measurements. The mean clinical follow-up duration for the 33 patients was (304.9±190.5) days, with 93.9% (31/33) of patients showing stable or improved neurological function compared to their preoperative status, and no cases of hematoma recurrence were observed. Compared to the concurrent with burr-hole drainage group, the MMA embolization alone group had a younger age [(71.9±9.7) years vs (81.4±9.9) years, t=2.620, P=0.013)], a lower preoperative modified Rankin Scale score [2 (1, 3) min vs 4 (2, 4) min, Z=2.471, P=0.017)], and less midline shift [4.5 (1.5, 6.0) mm vs 8.0 (7.0, 9.0) mm, Z=3.618, P<0.001]. Multivariate Logistic regression analysis showed that a younger age (OR=0.63, 95%CI: 0.41-0.97, P=0.038) and less midline shift (OR=0.07, 95%CI: 0.01-0.72, P=0.026) were independent predictors of successful MMA embolization alone.

Preliminary observations suggest that MMA embolization is a safe and effective treatment for cSDH and can be considered as a primary treatment modality. Furthermore, a younger age and a smaller degree of midline shift are independent predictors of successful treatment of cSDH with MMA embolization alone.