Single-Center Randomized Controlled Trial of Middle Meningeal Artery Embolization for Chronic Subdural Hematoma

Background

Embolization of the middle meningeal artery (MMA) for the treatment of chronic subdural hematoma (cSDH) has gained increasing acceptance since the publication of several nonrandomized studies that appear to demonstrate a high level of efficacy for the procedure both when performed as an adjunct to patients undergoing surgical drainage and when performed in minimally symptomatic patients treated without surgical drainage.

Methods

We conducted a single-center, randomized controlled trial (RCT) of MMA embolization in consecutive patients presenting to our hospital with cSDH from April 2020 to July 2023. Enrolled patients were randomized to standard of care (observation vs. surgical drainage per the treating neurosurgeon) or standard of care plus MMA embolization. The primary endpoint was the combined criteria of cSDH resolution (defined as < 5mm), resolution of clinical symptoms, no further intervention, and no major treatment-related complications.

Results

In total, 190 patients were screened, 46 were enrolled/randomized, and 1 withdrew immediately after randomization but before treatment. Accrual was ended early due to diminished enrollment; 79% of the accrual goal was achieved. Of the 45 study patients, 40 had sufficient follow up for primary outcome analysis. The primary endpoint was met by 14/20 (70%) in the control group and 15/20 (75%) in the MMA embolization group, respectively, p=0.5.

Conclusions

In this RCT, no significant difference was observed between standard of care and standard of care plus MMA embolization for cSDH. While the effect size appears to be smaller than that suggested by early case series, ongoing trials with greater statistical power may show benefit for the procedure.

Previously presented in abstract form at

New England Neurosurgical Society (NENS) 2024 Meeting

Key Messages

What is already known on this topic– Middle meningeal artery (MMA) embolization appears to be a safe and effective treatment for chronic subdural hematoma (cSDH), based on large case series. Randomized controlled trials of MMA embolization are just now being completed.

What this study adds– This study found no significant difference in the primary endpoint within 1 year (resolution of cSDH defined as < 5mm, no return of clinical symptoms, no need for further intervention, and no major treatment-related complications).

How this study might affect research, practice or policy– Further research, specifically RCTs with greater statistical power, are needed to better elucidate whether MMA embolization adds a statistically significant benefit to standard of care in cSDH.