arteriovenous malformation
Also written as: AVM — arteriovenous malformation
An abnormal tangle of blood vessels where arteries connect directly to veins without intervening capillaries, creating a high-flow vascular lesion.
Full Definition
An arteriovenous malformation (AVM) is a congenital vascular anomaly characterized by abnormal connections between arteries and veins without the normal intervening capillary bed. This creates a high-flow, low-resistance shunt that can lead to various complications. In the brain, AVMs may present with seizures, headaches, progressive neurological deficits, or catastrophic hemorrhage. The risk of bleeding varies with size, location, and angioarchitecture of the AVM. Pediatric patients may also present with congestive heart failure due to the high-flow nature of large AVMs. Diagnosis is typically made with MRI and confirmed with digital subtraction angiography. Treatment options include surgical resection, endovascular embolization, stereotactic radiosurgery, or a combination of these approaches, depending on the AVM characteristics and patient factors.
Usage
Usage note: Commonly abbreviated as AVM. Use hyphens in arteriovenous malformation.
In Context
- "The patient presented with acute hemorrhage from a previously undiagnosed arteriovenous malformation." — Emergency neurosurgical consultation
- "Stereotactic radiosurgery was recommended for the small, deep-seated AVM." — Multidisciplinary treatment planning