Arteriovenous fistula

Diagnosis

The specialist will use a stethoscope during physical examination to detect for abnormal blood flow in the arms and legs in order to identify an arteriovenous fistula. Additional tests are to confirm the diagnosis of a fistula.

An arteriovenous fistula may be detected by the following tests:

• Duplex ultrasound: A reliable method for detecting an arteriovenous fistula in the legs or arms which uses sound waves in to evaluate the rate of blood flow.
• Computerized tomography (CT) angiogram: If blood does not fill the capillaries, this imaging test can reveal it. This test involves the intravenous administration of substance (contrast). The contrast can be used to highlight internal body parts where blood flow does not bypass the capillaries as it should.
• Magnetic resonance angiography (MRA). If the patient develops symptoms of a deep-skin arteriovenous fistula, this test may be performed. An MRA is like an MRI, takes images of the body’s soft tissues using a magnetic field and radio waves. To make blood vessels more visible on pictures, contrast (dye) is administered intravenously.

Treatment

If an arteriovenous fistula is small and does not result in any other health issues then only monitoring is needed. There are cases that some small arteriovenous fistulas heal or close on their own without any medical intervention.

If the patient need treatment for an arteriovenous fistula, the specialist may recommend that following:

• Ultrasound-guided compression: could be used to treat an arteriovenous fistula in the legs that is clearly visible on ultrasonography. For around 10 minutes during this procedure, an ultrasound probe is pressed on the fistula. Blood flow to the damaged blood vessels is destroyed by compression.
  Catheter embolization: Most patients who have catheter embolization spend less than a day in the hospital for recovery and will be able to return to their normal routines within a week. In this procedure, a catheter is placed into an artery close to the arteriovenous fistula. Then, a tiny coil or stent is positioned at the location of the fistula to redirect blood flow.
• Surgery: If catheter embolization is ineffective in treating a large arteriovenous fistula, surgery may be necessary. The location and size of the arteriovenous fistula will determine which type of surgery is required. The specialist may repair the affected blood vessels by physically separating the two vessels or by removing a blood vessel from another part of your body and grafting it into the affected vessels.
• Radiation therapy: Destroying the link can sometimes be used to close a fistula that already exists. The fistula is precisely targeted by radiation therapy, which transforms it into scar tissue to prevent blood flowing through it.