The problem: recurrence
Chronic subdural haematoma (cSDH) is one of the most common neurosurgical conditions, particularly in older patients and those on anticoagulant or antiplatelet therapy. Surgical drainage is effective at relieving pressure, but the haematoma recurs in a proportion of patients (historically in the range of 10–20%). The substrate for recurrence is the vascularised membrane that forms around the collection, supplied by branches of the middle meningeal artery (MMA).
How MMA embolisation works
MMA embolisation is an endovascular procedure. Through arterial access at the wrist or groin, a microcatheter is navigated into the middle meningeal artery and its branches, and an embolic agent is delivered to devascularise the haematoma membranes. This reduces recurrent microhaemorrhage from the membranes and allows the collection to resorb. The procedure is typically brief and can be performed under sedation.
The evidence base
Following several years of observational data, three randomised controlled trials were published in the New England Journal of Medicine in late 2024: EMBOLISE, MAGIC-MT and STEM. Taken together, they support a reduction in recurrence and reoperation with a favourable safety profile, most clearly when embolisation is used as an adjunct to surgical drainage.
- EMBOLISE randomised patients undergoing surgical evacuation to adjunctive MMA embolisation or surgery alone, and reported a reduction in haematoma recurrence or progression requiring repeat surgery (approximately 4% versus 11%).
- MAGIC-MT and STEM examined broader populations, including patients managed without surgery, with results directionally consistent in reducing treatment failure and reoperation.
Open questions remain the subject of ongoing research, including choice of embolic agent, which patients benefit most, and the role of stand-alone embolisation in patients who would otherwise be observed. This is an area of active research interest for Dr Mitchelle.
Who should be considered?
- Recurrent cSDH after previous surgical drainage
- As an adjunct to surgery in patients at higher risk of recurrence, including those on anticoagulant or antiplatelet therapy that must continue
- Selected patients unsuitable for surgery, or with moderate collections under observation, where the aim is to prevent progression
cSDH management (observation, surgery, embolisation, or a combination) is planned with the treating neurosurgical team, taking into account the size of the collection, symptoms, medications and overall health.
Key references
Davies JM, et al. Adjunctive Middle Meningeal Artery Embolization for Subdural Hematoma (EMBOLISE). N Engl J Med. 2024;391:1890–1900.
Liu J, et al. Middle Meningeal Artery Embolization for Nonacute Subdural Hematoma (MAGIC-MT). N Engl J Med. 2024;391:1901–1912.
Fiorella D, et al. Embolization of the Middle Meningeal Artery for Chronic Subdural Hematoma (STEM). N Engl J Med. 2024.