An arteriovenous (AV) fistula is an abnormal connection between an artery and a vein. Normally, your blood flows from your arteries to your capillaries to your veins. Nutrients and oxygen in your blood travel from your capillaries to tissues in your body.
When you have an arteriovenous fistula, blood flows directly from an artery into a vein, bypassing the capillaries. When this happens, tissues downstream from the bypassed capillaries receive less blood supply.
Arteriovenous fistulas usually occur in the legs, but can also develop in the brain, lungs or arms.
You can be born with an arteriovenous fistula (congenital), or you can develop an arteriovenous fistula after some medical procedures. You can also develop an arteriovenous fistula from an injury that pierces the skin, such as a gunshot or stab wound. Leaving an arteriovenous fistula untreated can eventually lead to serious complications.
For people who have severe kidney disease, arteriovenous fistulas are sometimes surgically created in their forearms to make dialysis easier. If you have an arteriovenous fistula created, your doctors will closely monitor your condition to make sure you don't develop complications.
Small arteriovenous fistulas in your legs, arms, lungs or kidneys often won't have any symptoms and usually don't need treatment other than monitoring by your doctor. Larger arteriovenous fistulas may cause symptoms.
Arteriovenous fistula symptoms may include:
An arteriovenous fistula in your lungs (pulmonary arteriovenous fistula) is a serious condition and can cause:
When to see a doctor
Causes of arteriovenous fistulas include:
Left untreated, an arteriovenous fistula can cause complications, some of which can be serious. These include:
Preparing for your appointment
If you think you may have an arteriovenous fistula, make an appointment with your family doctor. If an arteriovenous fistula is found early, your treatment may be easier and more effective. Eventually, however, you may be referred to a vascular or heart specialist (cardiologist).
Because appointments can be brief, and because there's often a lot of ground to cover, it's a good idea to be prepared for your appointment. Here's some information to help you get ready for your appointment, and what to expect from your doctor.
What you can do
Your time with your doctor is limited, so preparing a list of questions will help you make the most of your time together. List your questions from most important to least important in case time runs out. For arteriovenous fistula, some basic questions to ask your doctor include:
In addition to the questions that you've prepared to ask your doctor, don't hesitate to ask questions during your appointment at any time that you don't understand something.
What to expect from your doctor
Tests and diagnosis
To diagnose an arteriovenous fistula, your doctor will use a stethoscope to listen to the blood flow through the area where he or she thinks you may have a fistula. The blood flow through an arteriovenous fistula makes a sound similar to clicking or humming machinery (machinery murmur).
If your doctor hears a machinery murmur, you'll have other tests to confirm that the murmur is caused by an arteriovenous fistula. These can include:
Treatments and drugs
It's possible your doctor may suggest only monitoring your arteriovenous fistula, especially if it's small and doesn't cause any other health problems. Some small arteriovenous fistulas close without treatment.
If your arteriovenous fistula requires treatment, your doctor may recommend catheter embolization. In this procedure, a catheter is inserted in an artery near the site of your arteriovenous fistula. Doctors use X-ray and other imaging techniques to guide the catheter to your fistula, and a small coil or stent is placed at the site of your fistula to reroute your blood flow. Many people who have catheter embolization stay in the hospital for 24 hours or less and can resume all their daily activities within a week.
Large arteriovenous fistulas that can't be treated with catheter embolization may require surgery. The type of surgery you'll need depends on the size and location of your arteriovenous fistula.
Last Updated: 2010-03-06
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