What is AV Fistula

August 20, 2019

An arteriovenous (AV) fistula is a connection that develops between an artery and a vein. Ideally, blood flows from arteries to the capillaries to your veins. For a person with AV fistula, the blood misses some of the capillaries and goes directly from an artery into a vein. As a result, the tissues that rely on the bypassed capillaries receive a lower supply of blood. Even though AV fistula usually occurs in the legs, they can also occur in your arms, kidneys, etc among others. Usually, smaller AV fistula don’t have any clear symptoms and are usually only monitored by the doctor and don’t require treatment. However, large fistulae needs to be treated and may lead to symptoms like bulging veins, varicose veins, swelling, low blood pressure, tiredness, and extreme cases may lead to heart failure. Pulmonary arteriovenous fistula can be detected by a bluish tinge on skin, traces of blood when coughing, and clubbing of the fingers and are serious.

If you see any of these symptoms, it is advisable to go see your doctor. Early detection of an AV fistula reduces the chance of it becoming more complicated since it might lead to complications like heart failure or blood clots.

Early diagnosis of an arteriovenous fistula is easier to treat and can also help avoid various risks and complications, such as heart failure, blood clots, etc. Visit your doctor immediately if you experience any of the signs and symptoms mentioned above. There are many potential causes for arteriovenous fistula.

  • Some cases of AV fistula can be present since birth. There isn’t an exact reason for the improper development of arteries or veins in the womb.
  • A genetic condition called Osler-Weber-Rendu Syndrome can cause abnormal development of blood vessels, especially the lung vessels, which can lead to arteriovenous fistula in the lungs.

There are also some medical procedures that can lead to AV fistula. Following are some of them:

  • Surgical creation for dialysis: Sometimes an AV fistula is surgically created to make it easier to perform dialysis on patients with late-stage kidney failure.
  • Complication to cardiac catheterization: During cardiac catheterization, a thin tube is inserted into either an artery or a vein in your groin, near your neck, or arm, and is threaded through the vessels to reach your heart. During this procedure, there is a very rare chance that the needle crosses a vein or artery and this can cause an AV fistula.

If the fistula is left untreated, it can lead to many other complications. Some of these can be pretty serious:

  • In case of an AV fistula, the blood flows much quicker when compared to the parts where it follows its routine path of arteries, capillaries, and veins. To compensate for this drop of blood pressure, the heart starts pumping blood much faster. Gradually, this extra strain on the heart muscles could weaken them which would cause to heart failure.
  • Usually an AV fistula in your legs can lead to blood clots which could potentially become more serious causing deep vein thrombosis. Thrombosis is an extremely painful condition which could potentially be fatal, especially if the clots manage to reach your lungs or brain.

There are many risk factors that could increase your risk of developing AV fistula. Other than genetic and birth defects, it can also be caused by hypertension, high BMI, older age. Sometimes medications like blood thinners or medicines being taken to control bleeding can also cause fistula. It is also more common in women.