Arteriovenous (AV) Fistula

When blood flows through your body, it moves from your arteries to your capillaries to your veins. With an arteriovenous (AV) fistula, blood bypasses some of the capillaries and flows directly from an artery into a vein. This causes tissues below the bypassed capillaries to receive less blood.

Small AV fistulas often don’t have symptoms, but large AV fistulas can be dangerous and require treatment.

The vascular surgery specialists at UPMC offer advanced treatment for AV fistula.

Looking for AV Fistula Care? 

On this page

• What Is AV Fistula?
• What Are the Symptoms of AV Fistula?
• How Do You Diagnose AV Fistula?
• How Do You Treat AV Fistula?

What Is AV Fistula?

An AV fistula is an abnormal connection between an artery and a vein.

When blood flows through the body, it moves from your arteries to your capillaries to your veins. With an AV fistula, blood bypasses some of the capillaries and flows directly from an artery into a vein. This causes the tissues below the bypassed capillaries to receive less blood.

How common is AV fistula?

The most common AV fistulas are deliberately created for people who need dialysis. The least common are those present at birth.

What are the types of AV fistulas?

AV fistulas can occur anywhere in the body but typically occur in the legs. Other common locations include the arms, lungs, kidneys, or brain.

What is the purpose of an AV fistula for dialysis?

A vascular surgeon creates an AV fistula to help people more easily connect to a dialysis machine for treatment. An AV fistula creates an access point where needles from the dialysis machine can be inserted into the blood vessels.

What causes an AV fistula?

An AV fistula can be caused by:

• Cardiac catheterization complications.
• Congenital defects.
• Genetic conditions.
• Injuries that pierce the skin.

What are AV fistula risk factors and complications?

AV fistula risk factors

You may be at higher risk for AV fistula if you:

• Are on dialysis.
• Had an injury that pierced your skin.
• Have a family history of AV fistula.
• Recent had a cardiac catheterization procedure.

Complications of AV fistula

Serious complications can develop if a large AV fistula is not treated, including heart failure, blood clots, leg pain, stroke, or bleeding.

Why do AV fistulas get so big?

The pressure of blood flowing from the artery directly into the vein causes the vein to enlarge, giving it a bulging, purplish appearance.

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 What Are the Signs and Symptoms of AV Fistula?

Small AV fistulas that occur in your legs, arms, lungs, kidneys, or brain often occur without any symptoms and only need to be monitored by your doctor. Larger AV fistulas may cause:

• Decreased blood pressure.
• Fatigue.
• Heart failure.
• Purplish, bulging veins that you can see through your skin, similar to varicose veins.
• Swelling in the arms or legs.
• Swelling, along with a reddish appearance on the skin surface.

Is AV fistula serious?

An AV fistula in your lung can cause serious symptoms, including:

• A bluish tint to your skin.
• Difficulty breathing (especially when exercising).
• Finger clubbing.
• Possible stroke.

When should I see a doctor about my AV fistula symptoms?

If you have an AV fistula, you should contact your doctor immediately. If you have severe symptoms, go to the nearest hospital emergency room or dial 911.

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How Do You Diagnose AV Fistula?

Your doctor may be able to diagnose an AV fistula during a physical exam. You may need other tests to confirm the diagnosis.

What to expect during your visit

During your physical exam, your doctor will:

• Ask about your symptoms and when they started.
• Discuss your medical history.
• Examine the affected area of your body.

Your doctor will place a stethoscope over the area where the fistula is suspected and listen for a sound similar to clicking or humming machinery (machinery murmur). If your doctor suspects you may have an AV fistula, they may order additional tests.

Tests to diagnose AV fistula

Your doctor will confirm your murmur is caused by AV fistula using one or more diagnostic tests, including:

• Duplex ultrasound – This is a painless test that uses sound waves to create images of the arteries in your legs. It also enables your doctor to measure blood flow through the arteries.
• CT ultrasound – This noninvasive test creates 3D images of soft tissue and blood vessels.
• Magnetic resonance angiography (MRA) – This test uses a large magnetic field, radio waves, and computers to make detailed pictures of your blood vessels and blood flow.

AV fistula prognosis

Some small AV fistulas may not require immediate treatment. However, large AV fistulas can cause serious symptoms if left untreated. Your doctor will recommend the best treatment for you based on the size and location of your fistula, as well as your symptoms.

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How Do You Treat AV Fistula?

At UPMC, our experts offer advanced treatment for AV fistula. Your doctor will recommend the best treatment option for you, which may include:

Monitoring

For small AV fistulas that don’t cause any other health problems, you will need to be monitored by your doctor. Your doctor may recommend routine follow-up visits to see if the fistula closes on its own.

Ultrasound-guided compression

This 10-minute nonsurgical procedure compresses the fistula under ultrasound guidance and blocks blood flow to the damaged blood vessels. Although it is noninvasive, it only works for about one in three people.

Minimally invasive catheter embolization

During a catheter embolization, your doctor will insert a catheter into a blood vessel and use x-ray or other imaging techniques to guide it to the site of your AV fistula. After the catheter is in place, your doctor will close the abnormal connection.

In some cases, your doctor may insert a small tube called a stent at the site of your fistula to reroute blood flow.

How effective is treatment?

AV fistula treatment is effective for managing symptoms and preventing complications.

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Why Choose UPMC for AV Fistula Care?

When you choose UPMC for AV fistula care, you will benefit from:

• Our coordinated treatment approach – Our team of endovascular and vascular surgeons works closely with other specialists to ensure complete care.
• Our vascular surgeons – As specialists in the surgical treatment of AV fistula, our vascular surgeons have the skills and expertise required to deliver outstanding outcomes.
• Our experience – Our experts perform hundreds of vascular procedures every year. UPMC is also a major referral center for people with AV fistula or other complicated vascular conditions.

By UPMC Editorial Staff. Last reviewed on 2024-10-01.