Arteriovenous fistula

Description

An arteriovenous (AV) fistula is an irregularity of the connection between an artery and a vein. Usually, the blood flows from the arteries to the small blood vessels (capillaries), and then in the veins. The nutrients and oxygen in your blood travel from the capillaries to the tissues in the body.

With an arteriovenous fistula, blood flows directly from an artery to a vein, avoiding some of the capillaries. When this happens, tissues below the avoided capillaries receive less blood.

Arteriovenous fistulas usually occur in the legs, but can develop in any part of the body. An arteriovenous fistula may be surgically created for use in dialysis in people with severe kidney disease.

The symptoms of arteriovenous fistulas depend on where they form in the body. A big without treatment of the arteriovenous fistula can lead to serious complications. The treatment of arteriovenous fistulas includes the monitoring, compression, catheter-based procedures and, sometimes, surgery.

Symptoms

Small arteriovenous fistulas in the legs, the arms, the lungs, the kidneys and the brain often have no signs or symptoms. Small arteriovenous fistulas usually do not need treatment other than monitoring by a health care provider. Large arteriovenous fistulas can cause signs and symptoms.

Arteriovenous fistula of the signs and symptoms may include:

  • Purple, bulging veins seen through skin, similar to varicose veins
  • Swelling in the arms or legs
  • Decreased blood pressure
  • Fatigue
  • Heart failure

An important arteriovenous fistula in the lungs (pulmonary arteriovenous fistula) is a serious condition that can cause:

  • Gray or blue, the lips or fingernails due to the lack of blood flow (cyanosis)
  • The tips of the toes to spread and become more round than normal (clubs)
  • Coughing up blood

An arteriovenous fistula in the digestive tract can cause gastrointestinal (GI) bleeding.

When to see a doctor

If you have signs and symptoms of an arteriovenous fistula, make an appointment to see your health care provider. The early detection of an arteriovenous fistula can cause the condition is easier to treat. It can also reduce the risk of developing complications, including blood clots, or heart failure.

Causes

Arteriovenous fistulas may be present at birth (congenital) or can occur later in life (acquired). Causes of arteriovenous fistulas are:

  • The injuries that pierce the skin. An arteriovenous fistula may be the result of a gunshot or a stab wound that occurs in one part of the body where a vein and artery are side by side.
  • Arteriovenous fistulas and congenital. In some babies, the arteries and the veins do not develop properly in the womb. It is not clear exactly why this happens.
  • Genetic conditions. Arteriovenous fistulas in the lungs (pulmonary arteriovenous fistulas) may be caused by a genetic disease that causes irregular blood vessels throughout the body, but especially in the lungs. One such disease, Osler-Weber-Rendu disease, also known as hereditary hemorrhagic telangiectasia.
  • Dialysis-related surgery. People have the last stage of kidney failure can have a surgery to create an arteriovenous fistula in the forearm to make it easier to perform the dialysis.

Risk factors

Certain genetic or congenital conditions increase the risk of arteriovenous fistula. Other possible risk factors for arteriovenous fistulas are:

  • Age
  • Sex female
  • Cardiac catheterization, particularly if the procedure involves the blood vessels of the groin
  • Certain medications, including some blood thinners (anticoagulants) and drugs that are used to control the bleeding (antifibrinolytics)
  • High blood pressure
  • The increase of body mass index (BMI)

Complications

Left untreated, an arteriovenous fistula can cause complications. Some complications can be serious. These include:

  • Heart failure. This is the most serious complication of a large arteriovenous fistula. The blood flows more quickly through an arteriovenous fistula, which is done through the typical blood vessels. The increased flow of blood that the heart pumps with more force. Over time, the strain on the heart can lead to heart failure.
  • The blood clots. An arteriovenous fistula in the legs can cause blood clots to form. Leg blood clots that can lead to a condition called deep vein thrombosis (DVT). deep vein thrombosis (DVT) can be fatal if the clot travels to the lungs (pulmonary embolism). Depending on where the fistula is, it can lead to a stroke.
  • Pain in the legs due to the lack of blood flow (claudication). An arteriovenous fistula can block the flow of blood to the muscles, causing pain in the leg.
  • Internal bleeding. The arteriovenous fistula can cause bleeding in the stomach and intestines.

Arteriovenous fistula

Diagnosis

To diagnose an arteriovenous fistula, a doctor may use a stethoscope to listen to the blood flow in the arms and legs. The blood flow through an arteriovenous fistula makes a sound like the buzzing.

If your doctor thinks you have a fistula, other tests are performed to confirm the diagnosis. Tests to diagnose an arteriovenous fistula may include:

  • The duplex ultrasound. Duplex ultrasound is the most effective and common to check if an arteriovenous fistula in the legs or arms. In the ultrasound, sound waves are used to assess the velocity of blood flow.
  • The computed tomography (CT) and angiography. This imaging test can show if the blood flow without passing through the capillaries. Dye (contrast material) is given INTRAVENOUSLY for this test. The dye helps the blood vessels to appear more clearly in the images.
  • The magnetic resonance angiography (MRA). This test may be done if you have signs of an arteriovenous fistula deep under the skin. As a magnetic resonance imaging, magnetic resonance angiography (MRA) uses a magnetic field and radio waves to create images of the body's soft tissues. Dye (contrast material) is given INTRAVENOUSLY to help the blood vessels to look better in pictures.

Treatment

If an arteriovenous fistula is small and does not cause other health problems, close monitoring by a health care provider may be the only treatment needed. Some small arteriovenous fistulas close by themselves without treatment.

If an arteriovenous fistula requires treatment, your doctor may recommend:

  • Ultrasound-guided compression. This may be an option for an arteriovenous fistula in the legs that is easily seen on ultrasound. In this treatment, an ultrasound probe push down into the fistula for about 10 minutes. The compression destroys the flow of blood to the damaged blood vessels.
  • Catheter embolization. In this procedure, a thin flexible tube (catheter) that is inserted into an artery near the arteriovenous fistula. Then, a small coil or stent is placed in the site of the fistula in order to divert the flow of blood. Many people who have catheter embolization remain in the hospital for less than a day and can resume their daily activities within a week.
  • Surgery. Large arteriovenous fistula that cannot be treated with catheter embolization may require surgery. The type of surgery needed depends on the size and location of the arteriovenous fistula.

Preparing for your appointment

If you think you may have an arteriovenous fistula, make an appointment with your primary care provider. You may be referred to a doctor trained in the blood vessels (vascular) or heart (cardiologist) diseases.

Appointments can be brief. Because there is often a lot of ground to cover, it is a good idea to be prepared for your appointment. Here's some information to help you prepare for your appointment and know what to expect from your doctor.

What you can do

  • Write down the symptoms you are experiencing, including any that may seem unrelated to the arteriovenous fistula.
  • Write down key personal information, including previous drilling of injury or family history of arteriovenous fistulas or other diseases of the blood vessels.
  • Make a list of all medications, vitamins or supplements you are taking. Include your dose.
  • Have a family member or friend along, if possible. Sometimes it can be difficult to remember all the information provided to you during an appointment. Someone who goes with you may remember something that you missed or forgot.
  • Write questions to ask their health care provider.

For an arteriovenous fistula, some basic questions to ask include:

  • What is the most likely cause of my symptoms?
  • There are other possible causes of the symptoms?
  • What kind of proof do you need?
  • What treatments are available, and which do you recommend?
  • What is an appropriate level of physical activity?
  • I have other health conditions. How can I best manage these conditions?
  • Should my children or other biological relatives are screened for this condition?
  • Are there brochures or other printed material that I can take my house? What sites do you recommend to visit?

What to expect from your doctor

Your doctor will probably ask a lot of questions. Be prepared to answer them you can save your time to go through all the information that you want to spend more time. Your provider may ask:

  • When did you first start having symptoms?
  • Do you always have symptoms, or come and go?
  • How severe are the symptoms?
  • Nothing seems to improve the symptoms?
  • What, if anything, makes symptoms worse?
Symptoms and treatment of the Arteriovenous fistula