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Arteriovenous Fistula

By James D. Douketis, MD, Professor, Divisions of General Internal Medicine, Hematology and Thromboembolism, Department of Medicine; Director, Vascular Medicine Research Program, McMaster University; St. Joseph's Healthcare Hamilton

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An arteriovenous fistula is an abnormal communication between an artery and a vein.

An arteriovenous fistula may be congenital (usually affecting smaller vessels) or acquired as a result of trauma (eg, a bullet or stab wound) or erosion of an arterial aneurysm into an adjacent vein.

The fistula may cause symptoms and signs of

Emboli (eg, causing ulceration) may pass from the venous to the arterial circulation, although pressure differences make this unlikely. If the fistula is near the surface, a mass can be felt, and the affected area is usually swollen and warm with distended, often pulsating superficial veins.

A thrill can be palpated over the fistula, and a continuous loud, to-and-fro (machinery) murmur with accentuation during systole can be heard during auscultation.

Rarely, if a significant portion of cardiac output is diverted through the fistula to the right heart, high-output heart failure develops.


  • Clinical evaluation

  • Sometimes ultrasonography

Fistulas are diagnosed clinically based on presence of thrill, murmur and other signs. Doppler ultrasonography is the best confirmatory test.


  • Sometimes percutaneous occlusion techniques

  • Sometimes surgery

Congenital fistulas need no treatment unless significant complications develop (eg, leg lengthening in a growing child). When necessary, percutaneous vascular techniques can be used to place coils or plugs into the vessels to occlude the fistula. Treatment is seldom completely successful, but complications are often controlled. Acquired fistulas usually have a single large connection and can be effectively treated by surgery.