Pulmonary Arteriovenous Fistula

What are the other Names for this Condition? (Also known as/Synonyms)

• Arteriovenous Fistula of Lung
• PAVM (Pulmonary Arteriovenous Malformation)
• Pulmonary Arteriovenous Malformation (PAVM)

What is Pulmonary Arteriovenous Fistula? (Definition/Background Information)

• Pulmonary Arteriovenous Fistula is an abnormal communication between the blood vessels carrying the oxygenated blood (pulmonary veins) and deoxygenated blood (pulmonary arteries).
• Most individuals may have the condition since birth (congenital occurrence), but it can also be an acquired condition occurring due to liver failure and trauma to the chest
• Most individuals with Pulmonary Arteriovenous Fistula also have a genetic condition called hereditary hemorrhagic telangiectasia. Patients with hereditary hemorrhagic telangiectasia have abnormal vessels in many parts of the body including the lungs
• The common signs and symptoms of Pulmonary Arteriovenous Fistula are shortness of breath, coughing-up blood, chest pain, dizziness, and syncope
• The condition cannot be prevented. Pulmonary Arteriovenous Fistula is treated with embolization and surgery and the prognosis is good with appropriate treatment

Who gets Pulmonary Arteriovenous Fistula? (Age and Sex Distribution)

• Pulmonary Arteriovenous Fistula is an uncommon condition. It is seen in infants, children, and adults
• They are more common in females than males

What are the Risk Factors for Pulmonary Arteriovenous Fistula? (Predisposing Factors)

The most important risk factor for Pulmonary Arteriovenous Fistula is the presence of hereditary hemorrhagic telangiectasia, a type of genetic disorder that runs in families.

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases ones chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.

Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.

What are the Causes of Pulmonary Arteriovenous Fistula? (Etiology)

• The exact cause of Pulmonary Arteriovenous Fistula is unknown
• In many individuals, the condition has a congenital onset (occurring at birth); but in some, the disorder occurs due to other medical conditions such as hepatic cirrhosis (liver failure) and chest trauma
• Pulmonary Arteriovenous Fistula can also be seen in children who have undergone surgery for congenital heart disease, as a complication of the procedure

What are the Signs and Symptoms of Pulmonary Arteriovenous Fistula?

The signs and symptoms of Pulmonary Arteriovenous Fistula include:

• Shortness of breath: Increased shortness of breath in upright position (platypnea), relieved by lying down
• Chest pain, cough that may contain blood in phlegm (hemoptysis)
• Migraine headaches, dizziness, syncope (fainting)
• Ringing in the ears, double vision
• Telangiectasias: It refers to small dilated tiny blood vessels (capillaries) on the skin and mucous membranes. They are generally seen in those having underlying hereditary hemorrhagic telangiectasia with Pulmonary Arteriovenous Fistula. They appear as ruby-colored, flat, sharply demarcated tiny lesions that blanch (turn pale) easily on pressure. These are generally seen on face, tongue, lips, and distal upper extremities
• Cyanosis: The skin on the tips of fingers, nose, and ear lobes turn blue, due to a lack of oxygen supplied to these parts

How is Pulmonary Arteriovenous Fistula Diagnosed?

The diagnosis of Pulmonary Arteriovenous Fistula may include:

• Complete evaluation of medical history along with a thorough physical exam
• If the individual suffers from hypoxia and orthodeoxia, it may signal the presence of Pulmonary Arteriovenous Fistula. Hypoxia refers to decrease in oxygen level in blood and orthodeoxia refers to decreased oxygen level in blood on standing upright
• X-ray and CT scan of chest: Special images of the chest may be taken that can help the physician make a diagnosis of Pulmonary Arteriovenous Fistula. The CT scan is more sensitive than a chest x-ray in establishing a diagnosis
• Pulmonary angiogram: A study to visualize blood vessels of the lungs after injecting a dye into the bloodstream

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.

What are the possible Complications of Pulmonary Arteriovenous Fistula?

Pulmonary Arteriovenous Fistula is associated with variety of complications, some of which may be life-threatening. These may include:

• Stroke: Stroke refers to the blockage of the blood supply to a part of the brain (ischemic), or bleeding in a blood vessel in the brain. Ischemic stroke is associated with PAVM (Pulmonary Arteriovenous Malformation) and may present as weakness or numbness of any part of body, difficulty to speak, or asymmetry of the face
• Bleeding in the lung
• Brain abscess: Brain infection with pus formation
• Recurrence of the condition after treatment

How is Pulmonary Arteriovenous Fistula Treated?

Typically, individuals with mild conditions presenting no symptoms may not require any treatment. In others, the treatment of Pulmonary Arteriovenous Fistula may include:

• Most patients are treated with embolization (a substance is injected to block the fistula)
• Surgery may be required in a few cases not responding to embolization, or in those with severe symptoms. During surgery, the abnormal vessels are removed along with surrounding lung tissue
• Those with liver failure may require a liver transplantation

How can Pulmonary Arteriovenous Fistula be Prevented?

Currently, there are no effective preventive measures available for Pulmonary Arteriovenous Fistula.

What is the Prognosis of Pulmonary Arteriovenous Fistula? (Outcomes/Resolutions)

• With suitable treatment the prognosis of Pulmonary Arteriovenous Fistula is good
• Majority of the individuals respond well to treatment and the condition usually does not recur

Additional and Relevant Useful Information for Pulmonary Arteriovenous Fistula:

• A CT scan of chest is used to diagnose various chest conditions, such as lung diseases, pneumonia, TB, lung cancer, injury to the ribs, etc.

The following article link will help you understand CT scan of chest:

http://www.dovemed.com/common-procedures/radiology-procedures/ct-scan-of-chest/