Questions About AV Fistulas

Arteriovenous fistula (AV fistula) is a condition where there is an abnormal connection between a vein and an artery. In some cases, doctors create AV fistulas to help patients whose kidneys have failed. The Encyclopedia of Surgery defines this type of AV fistula as "the connection of a vein and artery, usually in the forearm, to allow access to the vascular system for hemodialysis."

What are the symptoms of AV fistula?

• In a normal human system, blood flows in the veins from the arteries to the capillaries, supplying oxygen and nutrients to the tissues. When there is an AV fistula, blood flows directly into veins from arteries, cutting off the capillaries and starving the tissues of essential nutrients and oxygen from normal blood supply. The symptoms of AV fistulas depend on where they have formed, and on the size. AV fistulas can form in the lungs, legs, brain or arms. Small AV fistulas in the arms, legs, and lungs do not show much symptoms and usually only require monitoring by a doctor. Larger AV fistulas are more serious and manifest such symptoms as blueness of the skin, bloody sputum, difficulty in breathing, and nosebleeds.

What are the causes of AV fistula?

• Some people are born with AV fistula. A genetic disease known as Rendu-Osler-Weber increases the propensity of blood vessels in the body to develop abnormally. Also, some kinds of injuries lead to the development of AV fistula. Examples of such injuries are stab or gunshot wounds which pierce the skin near a place where veins and arteries are jointly located. Doctors intentionally create AV fistula in patients with kidney problems to widen a vein and connect it to a nearby artery. This causes the blood to flow faster and makes it easier to insert a needle for dialysis.

What are the Treatments for AV fistula?

• Small AV fistulas only require monitoring by a doctor. One of the treatments for AV fistulas is to have a catheter inserted in an artery located near the site of the AV fistula. A doctor consequently places a small stent at the site of the fistula to redirect the flow of blood. On the other hand, if the AV fistula is too complicated for catheters, surgery will be required.

What Happens if I don't Seek Treatment for AV fistula?

• If left untreated, AV fistula can result in serious complications. One of the complications is heart failure (from large AV fistulas). This as a result of the drop in blood pressure from the fast flow of blood in AV fistula, as opposed to normal arteries and veins. The heart has to pump harder to compensate for this low blood pressure, weakening the heart muscles and eventually leading to heart failure. Another danger is the formation of blood clots which can lead to a stroke, pulmonary embolism, or deep-vein thrombosis.