Management of Chronic Subdural Hematoma With Adjunctive Embolization of Middle Meningeal Artery
Importance: Chronic subdural hematomas commonly recur after surgical drainage. The effect of adjunctive embolization of the middle meningeal artery (EMMA) on recurrence risk remains unclear. Objective: To evaluate whether EMMA as an adjunct to surgical drainage reduces chronic subdural hematoma recurrence compared with surgery alone. Design, Setting, and Participants: This trial was a randomized, open-label, blinded-end point trial involving adults with unilateral, symptomatic chronic subdural hematoma (≥10 mm) undergoing surgical drainage across 9 tertiary care centers in Canada between August 2021 and April 2025. Intervention: EMMA using a liquid embolic agent (Onyx-18) within 72 hours after surgical drainage vs a control group that did not receive EMMA after surgical drainage. Main Outcomes and Measures: Primary outcome was symptomatic recurrence of chronic subdural hematoma detected on computed tomographic (CT) scan at 90 days (range, 60 to 120 days). Secondary outcomes included radiographic recurrence of chronic subdural hematoma, 90-day mortality, and serious adverse events. The last date of follow-up was July 27, 2025. Results: Of 192 randomized participants, 186 (mean age, 71.8 years; 136 male [73%]) completed the trial (93 per group). The primary outcome of symptomatic recurrence of chronic subdural hematoma detected on CT scan occurred in 4 participants (4.3%) in the EMMA group vs 26 patients (28%) in the control group (risk difference, -23.7; 95% CI, -34.1 to -13.9; P < .001). Radiographic recurrence occurred in 13 participants (14%) in the EMMA group vs 46 patients (49.5%) in the control group. Mortality was 4.3% vs 1.1%; serious adverse events occurred in 8.6% vs 5.4%, respectively. Conclusions and Relevance: Adjunctive EMMA after surgical drainage significantly reduced symptomatic recurrence on CT scan of unilateral chronic subdural hematoma at 90 days compared with surgery alone. Trial Registration: ClinicalTrials.gov Identifier: NCT04750200.
Authors
- Marlise P. dos Santos (ORCID: https://orcid.org/0000-0002-7489-0822)
- Benjamin Blackwood
- Maksim Son (ORCID: https://orcid.org/0000-0001-7827-7163)
- Susan Alcock
- Betty Anne Schwarz (ORCID: https://orcid.org/0009-0000-1222-6136)
- Alysa Almojuela (ORCID: https://orcid.org/0000-0002-3343-7546)
- Zul Kaderali (ORCID: https://orcid.org/0000-0002-2866-7160)
- Alwyn Gomez (ORCID: https://orcid.org/0000-0002-3737-2065)
- U Ahmed
- Amanda Martyniuk
- Howard Lesiuk (ORCID: https://orcid.org/0000-0001-5683-1899)
- Neil Berrington
- Guylaine Gévry (ORCID: https://orcid.org/0000-0003-1982-3480)
- Namita Sinha (ORCID: https://orcid.org/0000-0002-0234-1170)
- Jeremy Rempel
- Roland Jabre (ORCID: https://orcid.org/0000-0003-4102-2006)
- Geneviève Milot (ORCID: https://orcid.org/0000-0002-2847-8482)
- Kislay Kishore (ORCID: https://orcid.org/0000-0001-5754-9270)
- Sylvine Carrondo-Cottin
- Chiraz Chaalala (ORCID: https://orcid.org/0000-0001-6079-1455)
- R Balshaw
- J. Gauri Shankar
- Jason Beiko (ORCID: https://orcid.org/0000-0001-6457-3519)
- Reva Trivedi
- J McEachern
- Nishita Singh (ORCID: https://orcid.org/0000-0003-3647-0904)
- Nima Kashani (ORCID: https://orcid.org/0000-0002-9752-784X)
- Cassandra Tyson
- Julia MacMillan
- Bijoy K. Menon (ORCID: https://orcid.org/0000-0002-3466-496X)
- A Diouf
- Bill Wang (ORCID: https://orcid.org/0000-0003-2708-0955)
- C R Stalker
- Areej Fageeh (ORCID: https://orcid.org/0009-0007-3222-4200)
- Sara Chakir
- Colin Kazina
- Perry Dhaliwal (ORCID: https://orcid.org/0000-0002-5996-0757)
- Yan Sin Leung
- Sudeshna Bhattacharya
- Roman Marin (ORCID: https://orcid.org/0000-0003-1585-8053)
- Tom Marotta
- Almunder Algird
- Ramiro Larrazabal
- Sylvia Gaucher
- Josh Dian
- Vitor Mendes Pereira (ORCID: https://orcid.org/0000-0002-6804-3985)
- Nicole Mikhael
- Ian Fleetwood
- Joseph Silvaggio
- Marco Ayroso
- C J O’Kelly
- Gary Hunter
- Kowsiya Jeganathan
- Brian van Adel
- Daniela Iancu
- Adela Cora
- Depeng Jiang
- Brian Drake
- Mohammed Suheel Abdul Salam
- Michael E Kelly
- Frederick A Zeiler
- Nima Kashani
- Tim Darsaut
- Lissa Peeling
- Gwenydd Pickett
- Gil Zur
- Robert Fahed
- Santhosh Annayappa
- Rajiv Hira
- Julian Spears
- Sydney Targerson
- Patrick McDonald
- Adrienne Weeks
- Annie Drapeau
- EMMA-Can investigators
- Nicole Sylvain
- Eileen Liu
- Aaron Gardner
- Sandra Chanthavisouk
- Anthony Kaufmann
- Stephanie Shenassa
- Kaitlyn Foster
- Steven Cooper
- Ira Shankar
- Romika Mehta
- Kelly Villeneuve
- Michael Chow
- Beili Huang
- Jessica Grosskleg
Institutions
- Manitoba Health (CA)
- St. Michael's Hospital (CA)
- Dalhousie University (CA)
- University of British Columbia (CA)
- University of Ottawa (CA)
- University of Alberta (CA)
- University of Calgary (CA)
- University of Toronto (CA)
- University of Victoria (CA)
- Ottawa Hospital (CA)
- Karolinska Institutet (SE)
- University of Saskatchewan (CA)
- Pan Am Clinic (CA)
- Swedish Research Council for Environment Agricultural Sciences and Spatial Planning (SE)
- Centre Hospitalier de l’Université de Montréal (CA)
- Université Laval (CA)
- University of Manitoba (CA)
- McMaster University (CA)
Publication Details
- Journal
- JAMA
- Published
- 2026-04-30
- DOI
- https://doi.org/10.1001/jama.2026.4910
- Primary Topic
- Neurosurgical Procedures and Complications
- Type
- article
- Field-Weighted Citation Impact
- 0.00