An arteriovenous fistula is an abnormal channel between an artery and a vein.
Rarely, a large fistula may divert enough blood to cause symptoms of reduced blood flow in the affected arm or leg (steal syndrome).
Although doctors may be able to hear the distinctive sound of blood flow though a fistula by using a stethoscope, imaging tests are often needed.
A surgeon creates an arteriovenous fistula by making a connection between an artery (which carries blood away from the heart) and a vein (which carries blood back to the heart). This artificial connection allows the vein to become larger and for the walls of the vein to thicken, a process termed maturation.
When congenital arteriovenous fistulas are near the surface of the skin, they may appear swollen and reddish blue. In conspicuous places, such as the face, they appear purplish and may be unsightly.
Arteriovenous fistula signs and symptoms may include:
- Purplish, bulging veins that you can see through your skin, similar to varicose veins.
- Swelling in the arms or legs.
- Decreased blood pressure.
- Heart failure.
For congenital fistula, endovascular treatment.
For acquired fistulas, surgery.
Congenital arteriovenous fistulas usually need treatment only if they cause symptoms. When necessary, doctors usually do an endovascular procedure to block the abnormal connection between the artery and vein. This procedure is done using a small flexible tube (catheter) to inject coils or plugs into the abnormal connection.
Acquired arteriovenous fistulas usually have a single, large connection that can be corrected by a surgeon as soon as possible after diagnosis.