Arteriovenous Fistula

Diagnosis

To diagnose an arteriovenous fistula (AVF), a healthcare provider typically begins with a physical examination. Using a stethoscope, the provider listens for abnormal blood flow sounds in the arms or legs. The blood passing through an AVF often produces a humming or whooshing sound.

If an AVF is suspected, additional tests may be performed to confirm the diagnosis. Common diagnostic tests include:

Duplex Ultrasound. This is the most common and effective method to detect AVFs in the arms or legs. It uses high-frequency sound waves to evaluate the speed and direction of blood flow in the vessels.

Computerized Tomography (CT) Angiogram. This imaging test visualizes whether blood is bypassing the capillary network. A contrast dye is injected intravenously to make the arteries and veins more visible on the CT images.

Magnetic Resonance Angiography (MRA). If the AVF is located deep under the skin, an MRA may be used. This test works like an MRI, using a magnetic field and radio waves to create detailed images of soft tissues. A contrast dye may be given to enhance visibility of blood vessels.

Treatment

The treatment approach for an arteriovenous fistula depends on the size, location, and symptoms.

Observation. Small AVFs that do not cause symptoms may close naturally and only require regular monitoring by a healthcare provider.

Ultrasound-Guided Compression. This non-invasive treatment is used for AVFs that are easily seen on ultrasound, usually in the legs. An ultrasound probe applies pressure on the fistula for several minutes, redirecting blood flow and promoting closure.

Catheter Embolization. A minimally invasive procedure in which a thin catheter is inserted into an artery near the AVF. A small coil or stent is placed at the fistula site to reroute blood flow. Recovery is usually quick, with most patients resuming normal activities within a week.

Surgery. Large or complicated AVFs that cannot be treated with catheter embolization may require surgical intervention. The type of surgery depends on the fistula’s size and location, aiming to restore normal blood circulation and prevent complications.