Pulmonary arteriovenous fistula

Arteriovenous malformation - pulmonary

Pulmonary arteriovenous fistulas are usually the result of abnormal development of the blood vessels of the lung. Most occur in patients with Rendu-Osler-Weber disease (ROWD) – now commonly called hereditary hemorrhagic telangiectasia (HHT). These patients often have abnormal blood vessels in many parts of the body, including the lung.

Fistulas also can be a complication of liver disease or lung injury, although this is much less common.

Many people have no symptoms. When symptoms occur, they can include:

• Bloody sputum
• Difficulty breathing
• Difficulty exercising
• Nosebleeds
• Shortness of breath with exertion

Other possible symptoms include:

• Blue skin (cyanosis)
• Clubbing of the fingers

The doctor or nurse will examine you. The exam may show:

• Abnormal blood vessels (telangiectasias) on the skin or mucus membranes
• Abnormal sound, called a murmur when a stethoscope is placed over the abnormal blood vessel

Tests that may be done include:

• Arterial blood gas, with and without oxygen
• Complete blood count (CBC)
• Chest x-ray
• Chest CT scan
• Echocardiogram
• Liver function tests
• Perfusion radionuclide lung scan
• Pulmonary arteriogram

A small number of patients who have no symptoms may not need treatment. For most patients with fistulas, the treatment of choice is to block the fistula during an arteriogram (embolization).

Some patients may need surgery to remove the abnormal vessels and nearby lung tissue.

When arteriovenous fistulas are caused by liver disease, the treatment is a liver transplant.

The outlook for patients with HHT is not as good as for those without HHT. For patients without HHT, surgery to remove the abnormal vessels usually has a good outcome, and the condition is not likely to return.

Major complications after treatment for this condition are unusual. Complications may include:

• Bleeding in the lung
• Stroke due to blood clot that travels from the lungs to the arms, legs, or brain (paradoxical venous embolism)
• Infection in the brain or heart valve, especially in patients with HHT

Call your health care provider if you often have nosebleeds or difficulty breathing, especially if you also have a personal or family history of HHT.

Because this condition is often genetic, prevention is not usually possible.