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.

The authors have declared no competing interest.

NCT04270955

This study did not receive any funding.

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Ethics committee/IRB of Dartmouth-Hitchcock Medical Center/Dartmouth Health gave ethical approval for this work.

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* Co-first authors

Credentials and email information

1. Armin D. Tavakkoli, BA: armin.d.tavakkoli.meddartmouth.edu

2. Julio D. Montejo, MD, MHS: jd.montejogmail.com

3. Katelyn E. Salotto, BS: kate.salotto.meddartmouth.edu

4. Zabiullah Bajouri, MD: Zabiullah.Bajourihitchcock.org

5. William J. Smith, MD: wsmith13mgh.harvard.edu

6. Caitlin A. Payne, MD: caitlin.a.paynehitchcock.org

7. James E. Lee, MD: jamese.lee123gmail.com

8. John H. Kanter, MD: john.kanterucsf.edu

9. Imad S. Khan, MBBS, MPH: imadkhanuw.edu

10. Vyacheslav I. Makler, DO: vyacheslav.i.makler.milhealth.mil

11. Evalina Bond, MD: evalina.bondhitchcock.org

12. Kelsey P. Kinsman, MD: kelsey.p.kinsmanhitchcock.org

13. Stephanie A. Ihezie, MD: stephanie.a.iheziehitchcock.org

14. David Soucy, PA: david.soucyhitchcock.org

15. Barbara C. Badgley, APRN: barbara.c.badgleyhitchcock.org

16. Amber L. Porter, PA: amber.l.porterhitchcock.org

17. Beverly A. Allen, BA: beverly.a.allenhitchcock.org

18. Stephen J. Guerin, MD: stephen.j.guerinhitchcock.org

19. Naser Jaleel, MD, PhD: naser.jaleelbcm.edu

20. Daniel R. Calnan, MD, PhD: drcalnanmdgmail.com

21. Clifford J. Eskey, MD, PhD: clifford.j.eskeyhitchcock.org

Funding None

Conflict of interest None

All data produced in the present study are available upon reasonable request to the authors.