Arteriovenous Malformation
Overview
A brain arteriovenous malformation, or AVM, is a tangle of arteries and veins that disrupts normal blood flow and bypasses the usual capillary bed. AVMs vary widely in size, location, symptoms, and bleeding risk, so treatment planning must be individualized.
Treatment pathways can include observation, microsurgical removal, endovascular embolization, stereotactic radiosurgery, or a staged combination of these approaches.
How AVMs present
AVMs may be discovered after:
- Brain hemorrhage.
- Neurologic symptoms related to location.
- Incidental imaging findings.
How AVMs are diagnosed
AVM evaluation often includes:
- MRI of the brain.
- CT if bleeding is suspected.
- CTA or MRA.
- Diagnostic cerebral angiography to define feeding arteries, the nidus, venous drainage pattern, and associated aneurysms.
Microsurgical resection
Microsurgical resection is an open neurosurgical operation in which the AVM is disconnected from its feeding arteries, separated from surrounding brain, and removed.
Endovascular embolization
Endovascular embolization is a minimally invasive treatment performed through a catheter placed into the blood vessels. Embolic material is delivered into part or all of the AVM circulation to reduce or block abnormal blood flow.
Stereotactic radiosurgery
Stereotactic radiosurgery uses focused radiation to damage the abnormal AVM vessels over time, leading them to scar down and close.