Dural Arteriovenous Fistula (dAVF)

What is a dural arteriovenous fistula?

A dural arteriovenous fistula (dAVF) is an abnormal connection between an artery and vein within the protective cover around your brain and spinal cord (dura mater). This is a type of arteriovenous fistula.

Your blood vessels are in charge of transporting blood to your body’s organs, including your brain and spinal cord. Your arteries take oxygen-rich blood from your heart to organs throughout your body. Your veins carry oxygen-poor blood from your body’s organs back to your heart. Capillaries are tiny arteries that spread out the blood flow from major arteries to the organs they supply before they enter the veins.

Your body is used to having capillaries at the transition from arteries to veins. A fistula develops when an artery connects directly to a vein without a capillary in between. As a result, the artery pumps lots of blood into a vein that isn’t used to receiving so much blood flow.

A dAVF can disrupt the pressure in your blood vessels, change the size and shape of the vessel, and prevent blood from traveling in the direction it needs to go. Sometimes, a vessel can break or burst due to the pressure. This can lead to life-threatening bleeding.

You may hear your healthcare provider refer to dAVF as a dural arteriovenous malformation.

How common is a dural arteriovenous fistula?

In the United States, a dural arteriovenous fistula affects an estimated 0.15 to 0.19 out of 100,000 people each year.

Is a dural arteriovenous fistula serious?

Some dural arteriovenous fistulas are mild and won’t cause a major health complication, while others are very serious and can be life-threatening. If a vessel breaks and bleeding occurs, it can damage brain tissue and cause a stroke.

If you experience any symptoms, contact a healthcare provider. If you or a loved one show signs of a stroke, contact 911 or your local emergency services number immediately.

What are the symptoms of a dural arteriovenous fistula?

You might not have symptoms if you have a dural arteriovenous fistula (dAVF). If you do, symptoms range from mild to severe and may vary based on the location of the fistula. Symptoms may include:

• Headache.
• Nausea and vomiting.
• Hearing a constant noise (pulsatile tinnitus).
• Vision changes.
• Speech or language difficulties.
• Trouble with balance and coordination.
• Muscle weakness or numbness.
• Pain in your face, arms or legs.
• Memory loss.
• Abnormal feelings or sensations.

Symptoms are usually the result of bleeding within your brain. Contact a healthcare provider right away if you experience these symptoms.

What causes a dural arteriovenous fistula?

Healthcare providers aren’t sure of the exact cause of dural arteriovenous fistulas. Most scientists think that they result from head trauma even if the traumatic event happened years ago. Some studies suggest it could relate to a blockage in the vessels that carry blood away from your brain. An illness, injury or other event could cause the obstruction. For example:

• A blood clot (thrombosis).
• Traumatic brain injury.
• Brain surgery, like a craniotomy.

You can be born with a dAVF, but it isn’t hereditary. Research is still ongoing to learn more about this condition.

What are the risk factors for a dural arteriovenous fistula?

A dural arteriovenous fistula can affect anyone at any age. The condition is most common among adults between ages 40 and 60.

What are the complications of a dural arteriovenous fistula?

Complications of dAVF can be life-threatening and may include:

• Bleeding within your brain tissue (hemorrhage).
• Bleeding within your skull but outside of your brain (subdural hematoma).
• Bleeding between your brain and its protective coverings (subarachnoid hemorrhage).
• Pressure within your skull (intracranial pressure).
• Seizures.
• Stroke.

How is a dural arteriovenous fistula diagnosed?

A healthcare provider will make a dural arteriovenous fistula diagnosis after:

• A physical exam.
• A neurological exam.
• Imaging tests (radiology).

During your exams, your provider will ask you questions to learn more about your symptoms and medical history.

If you don’t have symptoms, a healthcare provider might make this diagnosis incidentally while performing an imaging test of your brain or spine for an unrelated reason.

Dural arteriovenous fistula radiology

A healthcare provider may use the following imaging tests to get a better look at your blood vessels to diagnose a dural arteriovenous fistula:

• A magnetic resonance imaging (MRI) scan or magnetic resonance angiography (MRA).
• A computed tomography angiography (CTA).

Both tests are painless and noninvasive. They help your provider get a more detailed view of the veins and arteries within your nervous system that may cause your symptoms.

If there’s suspicion of a dAVF on the imaging, your healthcare providers may talk with you about a diagnostic test called a cerebral angiogram.

A cerebral angiogram is a minimally invasive test that provides the best possible pictures of the vessels in your brain. Providers will place a tiny tube, called a catheter, in the artery at your wrist or at the top of your leg, and navigate the catheter to the vessels in your neck.

From the catheter, they’ll inject a contrast agent that mixes with your blood so they can take X-ray videos of the blood flowing into your brain’s arteries and out through your brain’s veins. This allows providers to better characterize the dAVF and determine how to best treat them.

Is there a cure for a dural arteriovenous fistula?

Treatment can remove the fistula and improve blood flow in your blood vessels as expected. It can reduce and prevent new symptoms and complications from happening.

How is a dural arteriovenous fistula treated?

The goal of dural arteriovenous fistula treatment is to remove the abnormal connection (fistula) between your artery and vein. Treatment options could include:

• Surgery: Open surgery can remove the fistula (abnormal connection) of the affected blood vessel.
• Endovascular embolization: This procedure uses a tiny tube, called a catheter, in your artery to reach the affected area and seal off the fistula.
• Stereotactic radiosurgery: This is a form of radiation therapy that uses focused beams of radiation directed at the affected blood vessel to block off the fistula connection.

Your healthcare provider will determine the best treatment plan for you based on the anatomy of the dAVF, your general health, symptoms and risk of bleeding or complications.

If you don’t have symptoms, your healthcare provider may not immediately treat the condition but offer regular monitoring to prevent complications.

Can a dural arteriovenous fistula be prevented?

There’s no known way to prevent a dural arteriovenous fistula (dAVF). You may be able to reduce your risk by managing any underlying health conditions that may lead to this condition, like blood clotting conditions. You can also protect yourself from injury by wearing the proper safety equipment for sports and activities.

What’s the prognosis for a dural arteriovenous fistula?

Your prognosis depends on many factors, like the location of the fistula and whether bleeding has occurred. With early discovery and treatment, your prognosis is positive. Unfortunately, some dural arteriovenous fistulas can lead to permanent or life-threatening complications. Follow-up care and support are available if complications happen, like physical therapy, occupational therapy and speech therapy.

Your healthcare provider will give you the most accurate outlook based on your situation.

Dural arteriovenous fistula survival rate

As dural arteriovenous fistulas aren’t common, research is still ongoing to learn more about survival rates. Current studies report that the annual mortality rate (the number of people who die due to this condition) is between 11% and 19%. This estimates the annual survival rate to be above 80% in certain cases.

When should I see a healthcare provider?

Contact a healthcare provider if you notice the following symptoms:

• A sudden, painful headache.
• Muscle weakness or numbness.
• Changes to your speech, balance or vision.
• New onset pulsatile tinnitus.

If you or a loved one experience symptoms of a stroke (one-sided weakness, slurred speech, confusion, etc.), contact 911 or your local emergency services number immediately.

What questions should I ask my healthcare provider?

• Where is the fistula?
• What type of treatment option do you recommend?
• Do I need surgery?
• Are there side effects of the treatment?
• Will a fistula return after treatment?
• How often do I need to schedule follow-up visits?