Middle Meningeal Artery Embolization Did Not Significantly Reduce Chronic Subdural Hematoma Recurrence

Middle meningeal artery (MMA) embolization with trisacryl gelatin microspheres (TAGM) did not significantly reduce chronic subdural hematoma (CSDH) recurrence at 6 months compared with standard medical care alone. While the results of the EMPROTECT clinical trial (NCT04372147), published in JAMA, show a numerically lower recurrence rate associated with embolization, the difference did not reach statistical significance.

The randomized clinical trial enrolled 342 individuals (median age, 77 years; 80% male) across 12 French neurosurgical centers from July 2020 to March 2023. Participants were adults at high risk of CSDH recurrence, defined as either surgery for CSDH recurrence or first-episode surgery with specific risk factors including anticoagulant therapy, chronic alcohol use, or surgery without external subdural drainage. Participants were randomized 1:1 to receive treatment with MMA embolization with 300- to 500-μm TAGM within 7 days of surgery or standard medical care. The primary endpoint was CSDH recurrence rate at 6 months, assessed by an independent, blinded adjudication committee.

• 14.8% of individuals in the embolization group experienced recurrence compared with 21% in the control group (adjusted odds ratio, .64; 95% CI, .36 to 1.14; P=.13).
• 4.3% of individuals in the embolization group required repeat surgery compared with 8.3% in the control group (P=.14).
• Embolization-related complications reported during the study include 1 major complication (stroke requiring thrombectomy) and 3 minor complications (transient neurologic deficits and minor headaches).
• No significant differences in mortality or disability rates between groups were reported.

The study demonstrates a reassuring safety profile for MMA embolization but falls short of statistical significance for efficacy. The study authors note that the magnitude of effect aligns with other recent trials using nonadhesive liquid embolic agents, suggesting the choice of embolic material may influence outcomes.

Source: Shotar E, Mathon B, Salle H, et al. Meningeal embolization for preventing chronic subdural hematoma recurrence after surgery: the EMPROTECT randomized clinical trial. JAMA. Published online June 5, 2025. https://doi.org/10.1001/jama.2025.7583