Merck Manual

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Arteriovenous Fistula

(AV Fistula)


James D. Douketis

, MD, McMaster University

Reviewed/Revised Sep 2022

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. In patients with end-stage renal disease requiring hemodialysis Hemodialysis In hemodialysis, a patient’s blood is pumped into a dialyzer containing 2 fluid compartments configured as bundles of hollow fiber capillary tubes or as parallel, sandwiched sheets of semipermeable... read more , an arteriovenous fistula is created surgically to provide vascular access for the procedure.

The fistula may cause symptoms and signs of

Emboli may pass from the venous to the arterial circulation (and cause ulceration when they lodge in distal vessels), 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.

Diagnosis of Arteriovenous Fistula

  • Clinical evaluation

  • Sometimes ultrasonography

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

Treatment of Arteriovenous Fistula

  • Sometimes percutaneous occlusion techniques

  • Sometimes surgery

Congenital fistulas need no treatment unless significant complications developing. 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.

NOTE: This is the Professional Version. CONSUMERS: View Consumer Version
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