n-Butyl Cyanoacrylate MMA Embolization in cSDH: Randomized Trial

Key Takeaways

• The primary effectiveness endpoint was reported less often with embolization plus standard care than with standard care alone.
• Adverse events through 6 months were not reported to increase significantly with embolization plus standard care.

Adults with symptomatic chronic subdural hematoma had fewer primary effectiveness events with middle meningeal artery embolization plus standard care than with standard care alone in the MEMBRANE randomized clinical trial. The trial compared middle meningeal artery embolization with TRUFILL n-butyl cyanoacrylate as an adjunct to usual management against standard care alone.

MEMBRANE was a prospective, multicenter, open-label randomized clinical trial conducted at 30 hospitals from May 27, 2021, to February 6, 2024. Sites included 28 hospitals in the United States and 2 in China. Participants were adults aged 18 to 90 years with symptomatic chronic subdural hematoma and modified Rankin Scale scores of 3 or less. Site physicians first determined surgical or nonsurgical management, then randomized patients 1:1 within those cohorts to embolization plus standard care or standard care alone. Among 376 enrolled participants, 188 entered each group; mean ages were 70.9 and 70.3 years, and female representation was 23.9% and 26.1%, respectively.

The primary effectiveness endpoint was residual or re-accumulation of hematoma greater than 10 mm at 6 months or need for cSDH surgery within 6 months. An independent core laboratory assessed the imaging component, and the comparison used an intention-to-treat analysis. Primary effectiveness events occurred in 17 of 146 participants receiving embolization plus standard care and 29 of 131 receiving standard care alone. That corresponded to 11.6% versus 22.1%, with a reported common odds ratio of 0.53, a 90% confidence interval of 0.31 to 0.91, and P = .04.

The primary safety endpoint was adverse events through 6 months, analyzed as-treated. Adverse events occurred in 130 of 181 participants in the embolization group and 124 of 190 in the standard care group. Those rates were 71.8% and 65.3%, and no significant increase in adverse events through 6 months was reported. MMA embolization plus standard care was also reported as noninferior for good functional outcome at 3 months by modified Rankin Scale.