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:
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 tube-like 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's 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 one in three 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.
Explore Mayo Clinic studies testing new treatments, interventions and tests as a means to prevent, detect, treat or manage this disease.
Preparing for your appointment
If you think you may have an arteriovenous fistula, make an appointment with your primary care doctor. At some point, however, you may be referred to a blood vessel (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 know what to expect from your doctor.
What you can do
- Be aware of any pre-appointment restrictions. At the time you make the appointment, be sure to ask if there's anything you need to do in advance, such as restrict your diet. Since tests for an arteriovenous fistula usually include an ultrasound, it's possible you'll need to fast for several hours before your appointment.
- Write down any symptoms you're experiencing, including any that may seem unrelated to an arteriovenous fistula.
- Write down key personal information, including previous piercing injuries or a family history of arteriovenous fistula or other blood vessel diseases.
- Make a list of all medications, vitamins or supplements that you're taking.
- Take a family member or friend along, if possible. Sometimes it can be difficult to recall all of the information provided to you during an appointment. Someone who accompanies you may remember something that you missed or forgot.
- Write down questions to ask your doctor.
Your time with your doctor is limited, so preparing a list of questions will help you make the most of your time together. For arteriovenous fistula, some basic questions to ask your doctor include:
- What's the most likely cause of my symptoms?
- Are there any other possible causes for my symptoms?
- What kinds of tests will I need?
- What treatments are available, and which do you recommend?
- What's an appropriate level of physical activity?
- I have other health conditions. How can I best manage these conditions together?
- Should my children or other blood-related relatives be screened for this condition?
- Are there any brochures or other printed material that I can take home with me? What websites do you recommend visiting?
What to expect from your doctor
Your doctor is likely to ask you a number of questions. Being ready to answer them may reserve time to go over any points you want to spend more time on. Your doctor may ask:
- When did you first begin experiencing symptoms?
- Have your symptoms been continuous or do they come and go?
- How severe are your symptoms?
- Does anything seem to improve your symptoms?
- What, if anything, appears to worsen your symptoms?