What guides the decision?
A specialist weighs your neurologic symptoms, the size and location of the hematoma, pressure on the brain, changes on repeat scans, and your other medical needs.
The immediate question is whether pressure must be relieved urgently. The longer-term question is how to help the collection resolve and reduce the chance of recurrence.
Treatment options at a glance
| Option | Main role | Important limitation |
|---|---|---|
| Observation | Follow selected small, stable collections with exams and imaging. | Requires reliable follow-up and a plan for worsening symptoms. |
| Surgical drainage | Remove blood and relieve pressure; the approach depends on the collection. | A chronic hematoma may recur after drainage. |
| MMA embolization | Reduce blood supply to the membranes sustaining a chronic collection. | Works gradually; carries vascular and neurologic risks. |
| Drainage + MMAE | Relieve pressure and reduce recurrence risk in appropriate patients. | Requires assessment of the benefits and risks of both procedures. |
When is surgery needed?
New neurologic deficits, deteriorating alertness, or concerning pressure on the brain may require emergency surgery. A neurosurgeon selects the approach. Burr-hole drainage uses a small opening to drain a suitable collection, often with a temporary drain. A craniotomy creates a larger opening and may be needed for solid clot or more complex bleeding.
MMAE is not a substitute for immediate decompression. A patient with an emergency should be assessed at a hospital rather than wait for an elective embolization consultation.
Where MMAE fits
For chronic subdural hematoma, the 2026 SNIS guideline recommends MMAE as an adjunct to drainage to reduce recurrence requiring another intervention, balanced against procedural risk. Standalone MMAE is reasonable in selected circumstances.
This is a substantial change in the evidence for chronic subdural care, but it does not mean every subdural bleed needs embolization. Acute bleeding and urgent pressure problems require a different assessment.
What about medication?
The team may adjust blood-thinning medication, treat a clotting problem, or prescribe medication for seizures when appropriate. Medication decisions depend on the reason for each drug and the risks of stopping it.
Do not stop, restart, or change aspirin, an anticoagulant, or another prescribed medicine without instructions from the treating team. Details: blood thinners and subdural hematoma.
Questions to ask your specialist
- Is the collection acute, chronic, or mixed?
- Is there pressure that requires urgent drainage?
- Would adding MMAE meaningfully reduce recurrence in my case?
- Is standalone MMAE an appropriate option for me?
- What are the procedural risks and alternatives?
- When should I have another scan, and who will review it?
- What is my plan for blood thinners and activity?
Sources & further reading
- MedlinePlus / National Library of Medicine — Subdural hematoma
- 2026 SNIS recommendations for MMA embolization in chronic subdural hematoma
- Davies et al. EMBOLISE — Adjunctive Middle Meningeal Artery Embolization for Subdural Hematoma. NEJM, 2024.
Educational content from Neurovascular Centers. Individual treatment decisions require a clinical examination and review of your imaging.