An arteriovenous malformation (AVM) of a limb is an abnormal tangle of vessels, present from birth, in which arteries connect straight to veins without capillaries in between. It often grows during puberty, pregnancy or after trauma, and can cause pain, skin damage, bleeding and, if large, heart failure from high blood flow.
Key symptoms
- Swelling or a mass in the arm or leg that grows over time
- A pulsing or buzzing feeling in the limb
- Pain, often worse with activity
- Skin color changes, ulcers or bleeding
- Difference in limb size
What you find on exam
- Warm, pulsatile mass with a palpable thrill
- Continuous bruit over the lesion
- Dilated veins, skin discoloration or ulcers
- Compare limb length and girth
- Distal pulses and signs of steal: cool, pale fingers or toes
Tests
- Duplex ultrasound: high-flow vessels and arteriovenous shunting
- MRI with MR angiography to map size and depth
- Catheter angiography to plan treatment
- Echocardiogram if heart failure is suspected
Treatment basics
- Watchful waiting for small lesions without symptoms
- Compression garments for pain and swelling
- Endovascular embolization, sometimes with sclerotherapy
- Surgical removal, often after embolization
- Care by a specialized vascular anomalies team
Red flags
- Heavy bleeding from the lesion
- Non-healing ulcer or skin breakdown
- Breathlessness or leg swelling suggesting high-output heart failure
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Sources: NCCPA PANCE Content Blueprint; NBOME COMLEX-USA clinical presentations; AAMC Core Entrustable Professional Activities (Core EPAs). Written by Making Synapses. Making Synapses is not affiliated with these organizations.