Single-Center Randomized Controlled Trial of Middle Meningeal Artery Embolization for Chronic Subdural Hematoma (Dart-Embo)

Introduction: The primary objective of this single-center randomized controlled trial was to evaluate the efficacy of middle meningioma artery (MMA) embolization for the treatment of chronic subdural hematoma (cSDH).

Methods: From April 2020 to July 2023, consecutive inpatients presenting to our institution with cSDH were screened based on age >= 18 years, convexity cSDH >= 7mm maximal coronal thickness and encompassing >= 50% of the hemisphere, cSDH not secondary to previous craniotomy/cerebrospinal fluid hypotension/shunt over-drainage/tumor/cyst/vascular malformation, able to follow up at our institution, life expectancy >= 6 months, consentable/appropriate surrogate decision maker, and not otherwise part of a vulnerable group (homeless/incarcerated). Enrolled patients were first categorized into symptomatic/asymptomatic and then evenly randomized to standard of care (observation vs. surgical drainage at the discretion of the treating neurosurgeon) vs. standard of care plus MMA embolization (predominantly microparticle-based). At 3, 6, and 12 months patients were assessed at clinic appointments and with non-contrast head computed tomography. The primary endpoint was evaluated in a blinded fashion and met if the cSDH resolved (defined as < 5mm maximal coronal thickness) at any of these time points and there was no return of clinical symptoms, no need for further intervention, and no major treatment-related complications.

Results: Patient accrual was ended early due to diminished enrollment. Seventy-eight percent of the midpoint interim analysis accrual goal was achieved. In total, 190 patients were screened, 46 were enrolled/randomized (38 symptomatic, 8 asymptomatic), and 1 withdrew immediately after randomization but before treatment. Of the remaining 45, 40 had sufficient follow up for primary outcome analysis. The primary endpoint was met by 14/20 (70%) vs. 15/20 (75%) (Fischer’s exact p = 0.5) in the control group vs. the MMA embolization group, respectively.

Conclusion : In this statistically underpowered single-center randomized controlled trial, no statistically significant difference was observed between standard of care and standard of care plus MMA embolization for cSDH. More trials are needed with greater statistical power.