arteriovenous malformation
Abnormal tangle of blood vessels connecting arteries and veins directly without normal capillary beds, creating high-flow vascular lesions.
Full Definition
An arteriovenous malformation (AVM) is a complex vascular anomaly characterized by abnormal connections between arteries and veins without intervening normal capillary beds. These lesions consist of a central nidus of abnormal vessels with enlarged feeding arteries and draining veins, creating high-flow, low-resistance circuits. AVMs can occur in various locations but are most clinically significant in the brain, where they pose risks of hemorrhage, seizures, and neurological deficits. Vascular imaging is crucial for AVM characterization, treatment planning, and post-treatment surveillance. The lesions demonstrate characteristic flow voids on MRI and early venous filling on angiographic studies.
Usage
Usage note: Commonly abbreviated as AVM; specify location and Spetzler-Martin grade when applicable.
In Context
- "The cerebral arteriovenous malformation measured 3 cm in maximum diameter with multiple feeding arteries." — Neurosurgical consultation
- "Post-embolization angiography confirmed complete obliteration of the AVM nidus." — Interventional procedure report