Arteriovenous (AV) Fistula
- By sahlhealth
- May 18, 2021
- 21 views
An Arteriovenous (AV) Fistula is an abnormal connection between an artery and a vein. Normally, 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.With an Arteriovenous fistula, blood flows directly from an artery into a vein, bypassing some capillaries. When this happens, tissues below the bypassed capillaries receive a diminished blood supply.Arteriovenous fistulas usually occur in the legs, but can develop anywhere in the body. Arteriovenous fistulas are often surgically created for use in dialysis in people with severe kidney disease.A large untreated Arteriovenous fistula can lead to serious complications. Your doctor monitors your Arteriovenous fistula if you have one for dialysis.
-Small Arteriovenous fistulas in your legs, arms, lungs, kidneys or brain often won't have any signs or symptoms and usually don't need treatment other than monitoring by your doctor. Large Arteriovenous fistulas may cause signs and symptoms.
Arteriovenous Fistula signs and symptoms may include:
- Purplish, bulging veins that you can see through your skin, similar to varicose veins
- Swelling in the arms or legs
- Decreased blood pressure
- Heart failure
-An Arteriovenous fistula in your lungs (pulmonary Arteriovenous fistula) is a serious condition and can cause:
- A bluish tinge to the skin
- Clubbing of fingers
- Coughing up blood
-An Arteriovenous fistula in your gastrointestinal tract can cause bleeding in your digestive tract.
When to see a doctor
-If you have any of these signs and symptoms and think you might have an Arteriovenous fistula, make an appointment to see your doctor. Early detection of an Arteriovenous fistula may make your condition easier to treat and may reduce your risk of developing complications, such as blood clots or, in severe cases, heart failure.
-To diagnose an Arteriovenous fistula in your arms or legs, 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 suspects a fistula, you'll have other tests to confirm your diagnosis. These can include:
- Duplex ultrasound. Duplex ultrasound is the most effective and common way to check for an Arteriovenous fistula in the blood vessels of your legs or arms. In duplex ultrasound, an instrument called a transducer is pressed against your skin over the suspicious area.The transducer produces high-frequency sound waves, which bounce off red blood cells. A duplex ultrasound can estimate how fast blood flows by measuring the rate of change in its pitch (frequency).
- Computerized tomography (CT) angiogram. A CT angiogram allows your doctor to check your arteries to see if blood flow is bypassing the capillaries. You'll receive an injection of a dye that shows up on CT images, and the doughnut-shaped CT scanner will be moved to take images of the artery your doctor believes is narrowed. The images are then sent to a computer screen for your doctor to view.
- Magnetic resonance angiography (MRA). Your doctor may use an MRA if he or she thinks you may have an Arteriovenous fistula in an artery that's deep under your skin. This test allows your doctor to see the soft tissues in your body. It uses the same technique as magnetic resonance imaging (MRI), but also includes the use of a special dye that helps create images of your blood vessels.During an MRI or MRA, you lie on a table inside a long tubelike machine that produces a magnetic field. An MRI machine uses the magnetic field and radio waves to create pictures of your body's tissues. Using the images from the test, your doctor may be able to see an Arteriovenous fistula.
-It's possible your doctor may suggest only monitoring your Arteriovenous fistula, especially if it is small and doesn't cause any other health problems. Some small Arteriovenous fistulas close by themselves without treatment.If your Arteriovenous fistula requires treatment, your doctor may recommend:
- Ultrasound-guided compression. If you have an Arteriovenous fistula in your legs and it's easily visible on ultrasound, treatment with ultrasound-guided compression may be an option for you. In this treatment, an ultrasound probe is used to compress the fistula and block blood flow to the damaged blood vessels.This procedure only takes about 10 minutes. But it only works for about 1 in 3 people.
- 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.
- Surgery. 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.