Pulmonary arteriovenous fistula
Pulmonary arteriovenous fistula is an abnormal connection between an artery and vein in the lungs. As a result, blood passes through the lungs without receiving enough oxygen.
Causes
Pulmonary arteriovenous fistulas are usually the result of abnormal development of the blood vessels of the lung. Most occur in people with hereditary hemorrhagic telangiectasia (HHT). These people often have abnormal blood vessels in many other parts of the body.
Hereditary hemorrhagic telangiectasia (...
Hereditary hemorrhagic telangiectasia (HHT) is an inherited disorder of the blood vessels that can cause excessive bleeding.
Read Article Now Book Mark ArticleFistulas also can be a complication of liver disease or lung injury, although these causes are much less common.
Symptoms
Many people have no symptoms. When symptoms occur, they can include:
- Bloody sputum
Bloody sputum
Coughing up blood is the spitting up of blood or bloody mucus from the lungs and throat (respiratory tract). Hemoptysis is the medical term for cough...
Read Article Now Book Mark Article - Difficulty breathing
Difficulty breathing
Breathing difficulty may involve:Difficult breathing Uncomfortable breathingFeeling like you are not getting enough air
Read Article Now Book Mark Article - Difficulty exercising
- Nosebleeds
- Shortness of breath with exertion
- Chest pain
Chest pain
Chest pain is discomfort or pain that you feel anywhere along the front of your body between your neck and upper abdomen.
Read Article Now Book Mark Article - Blue skin (cyanosis)
Cyanosis
A bluish color to the skin or mucous membrane is usually due to a lack of oxygen in the blood. The medical term is cyanosis.
Read Article Now Book Mark Article - Clubbing of the fingers
Clubbing
Clubbing is changes in the areas under and around the toenails and fingernails that occur with some disorders. The nails may also show changes....
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Exams and Tests
The health care provider will examine you. The exam may show:
- Abnormal blood vessels (telangiectasias) on the skin or mucous membranes
Telangiectasias
Telangiectasias are small, widened blood vessels on the skin. They are usually harmless, but may be associated with several diseases.
Read Article Now Book Mark Article - Abnormal sound, called a murmur when a stethoscope is placed over the abnormal blood vessel
- Low oxygen when measured with a pulse oximeter
Tests that may be done include:
- Arterial blood gas, with and without oxygen (usually oxygen treatment does not improve the arterial blood gas as much as expected)
Arterial blood gas
Blood gases are a measurement of how much oxygen and carbon dioxide are in your blood. They also determine the acidity (pH) of your blood.
Read Article Now Book Mark Article - Complete blood count (CBC)
Complete blood count
A complete blood count (CBC) test measures the following:The number of white blood cells (WBC count)The number of red blood cells (RBC count)The numb...
Read Article Now Book Mark Article - Chest x-ray
Chest x-ray
A chest x-ray is an x-ray of the chest, lungs, heart, large arteries, ribs, and diaphragm.
Read Article Now Book Mark Article - Chest CT scan
Chest CT scan
A chest CT (computed tomography) scan is an imaging method that uses x-rays to create cross-sectional pictures of the chest and upper abdomen....
Read Article Now Book Mark Article - Echocardiogram with bubble study to check the function of the heart and assess for presence of a shunt
Echocardiogram
An echocardiogram is a test that uses sound waves to create pictures of the heart. The picture and information it produces is more detailed than a s...
Read Article Now Book Mark Article - Lung function tests
Lung function tests
Pulmonary function tests are a group of tests that measure breathing and how well the lungs are functioning.
Read Article Now Book Mark Article - Perfusion radionuclide lung scan to measure breathing and circulation (perfusion) in all areas of the lungs
Perfusion radionuclide lung scan
A pulmonary ventilation/perfusion scan involves two nuclear scan tests to measure breathing (ventilation) and circulation (perfusion) in all areas of...
Read Article Now Book Mark Article - Pulmonary arteriogram to view the lung arteries
Arteriogram
An arteriogram is an imaging test that uses x-rays and a special dye to see inside the arteries. It can be used to view arteries in the heart, brain...
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Treatment
A small number of people who have no symptoms may not need treatment. For most people with fistulas, the treatment of choice is to block the fistula during an arteriogram (embolization).
Arteriogram
An arteriogram is an imaging test that uses x-rays and a special dye to see inside the arteries. It can be used to view arteries in the heart, brain...
Read Article Now Book Mark ArticleSome people 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.
Liver transplant
Liver transplant is surgery to replace a diseased liver with a healthy liver.
Read Article Now Book Mark ArticleOutlook (Prognosis)
The outlook for people with HHT is not as good as for those without HHT. For people without HHT, surgery to remove the abnormal vessels usually has a good outcome, and the condition is not likely to return.
For people with liver disease as a cause, prognosis depends on liver disease.
Possible Complications
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)
Stroke
A stroke occurs when blood flow to a part of the brain stops. A stroke is sometimes called a "brain attack. " If blood flow is cut off for longer th...
Read Article Now Book Mark Article - Infection in the brain or heart valve, especially in patients with HHT
When to Contact a Medical Professional
Contact your provider if you often have nosebleeds or difficulty breathing, especially if you also have a personal or family history of HHT.
Prevention
Because HHT is often genetic, prevention is not usually possible. Genetic counseling may help in some cases.
Genetic counseling
Genetics is the study of heredity, the process of a parent passing certain genes on to their children. A person's appearance, such as height, hair co...
Read Article Now Book Mark ArticleReviewed By
Denis Hadjiliadis, MD, MHS, Paul F. Harron, Jr. Professor of Medicine, Pulmonary, Allergy, and Critical Care, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.
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Stowell J, Gilman MD, Walker CM. Congenital thoracic malformations. In: Shepard JO, ed. Thoracic Imaging: The Requisites. 3rd ed. Philadelphia, PA: Elsevier; 2019:chap 8.
Valente AM, Dorfman AL, Babu-Narayan SV, Krieger EV. Congenital heart disease in the adolescent and adult. In: Libby P, Bonow RO, Mann DL, Tomaselli GF, Bhatt DL, Solomon SD, eds. Braunwald's Heart Disease: A Textbook of Cardiovascular Medicine. 12th ed. Philadelphia, PA: Elsevier; 2022:chap 82.