Initial data from the prospectively randomized G-MEMBRANE trial and systematic review on the embolization of the middle meningeal artery in the treatment of chronic subdural hematomas

Middle meningeal artery embolization (MMAE) is a promising treatment, as surgical treatment of chronic subdural hematoma (cSDH) still exhibits high recurrence rates. G-MEMBRANE is a single-center, investigator-initiated, prospectively randomized controlled trial (RCT) evaluating the efficacy of adjuvant MMAE. Patients with cSDH requiring surgery were randomly assigned to either surgery plus MMAE or surgery alone. The primary endpoint was cSDH recurrence within 3 months of follow-up. Assuming a risk difference of 20%, an interim analysis was planned after the enrollment of 77 patients. A systematic literature review identified all completed RCTs published between 2015 and 2025. The interim analysis included 93 randomized patients, 64 of whom were available for primary endpoint analysis. The drop-out and lost-to-follow-up rate of 19.1% in the control group and 43.5% in the intervention group were high. Mean age was 74.6 ± 13.3 years, 66.7% patients were male. In the intervention group, 5/26 patients (19.2%) developed recurrent cSDH, compared to 9/38 (23.7%) in the control group ( p = 0.672). Revision surgeries were performed in 0% in the intervention group and in 4 (10.5%) of the control group ( p = 0.140). No adverse events were related to MMAE. Eight RCTs were included in the systematic review with significant results reported in two large multicenter studies and two small single-center studies regarding “recurrences/reoperation.” The small risk difference between the study groups at the time of interim analysis led to the premature termination of the study which remains inconclusive. Considering the limitations and international study results, G-MEMBRANE provides preliminary information on safety and possible recurrence prevention of cSDH using MMAE for routine clinical practice. Trial registration: Prospectively registered on Nov. 11th, 2021 German Clinical Trials Registry (DRKS00020465).