Middle Meningeal Artery Embolization Using N-hexyl Cyanoacrylate Versus EVOH for Chronic Subdural Hematoma: a Retrospective Comparative Cohort Study

Chronic subdural hematoma (cSDH) has traditionally been treated surgically, with a ~ 20% risk of recurrence. Three RCTs have shown that middle meningeal artery embolization MMAE using EVOH-based liquid embolic agents (LEAs) reduces recurrence. Preliminary data suggest similar results with n-butyl-cyanoacrylate (NBCA). N‑hexyl-Cyanoacrylate (NHCA) may offer advantages over NBCA, but has not been compared with EVOH-based agents.

This retrospective multicenter study included patients from four centers treated with MMAE for cSDH using Squid (EVOH) or Magic Glue (NHCA). The primary endpoint was repeat surgical evacuation. The primary endpoint was analyzed using Kaplan-Meier estimates, the log-rank test, and Cox proportional hazards regression. Univariable and multivariable logistic regression was performed as a complementary adjusted analysis. Secondary endpoints were cSDH thickness reduction, modified Rankin Scale (mRS) at last follow up, and complications.

144 patients were included (120 males, mean age 75.2 ± 10.6 years). NHCA was used in 79 patients (54.9%) and EVOH in 65 (45.1%). In each group, 9 patients required repeat surgical evacuation (NHCA: 11.4% [95%CI: 5.3%, 20.5%], EVOH: 13.8% [95% CI: 6.5%, 24.7%]). Kaplan-Meier analysis showed no significant difference in freedom from repeat surgical evacuation between groups; Cox regression likewise showed no significant association between embolic agent and time to repeat surgery (HR 0.68, 95% CI 0.27-1.72; p = 0.42). Complementary multivariable logistic analysis did not identify a statistically significant association between the embolic agent and repeat surgery (adjusted OR 0.92, 95% CI 0.32-2.63; p = 0.87). Mean cSDH reduction was 12.4 ± 6.1 mm with NHCA and 13.8 ± 7.4 mm with EVOH (p = 0.18). Median mRS at last follow-up was 1 (IQR: 0, 2) in both groups (p = 0.64). Complications were reported in 6.3% (Magic Glue) and 4.6% (Squid, OR 1.4, 95% CI 0.3,6.9; p = 0.73).

This multicenter study found no statistically significant differences between NHCA and EVOH regarding repeat surgerical evacuation, cSDH reduction, mRS at last follow-up, and safety. However, the wide confidence intervals preclude conclusions of equivalence.