Dural arteriovenous fistula (DAVF)
What is dural arteriovenous fistula?
A dural arteriovenous fistula (DAVF) is a rare condition caused by an abnormal connection between arteries and veins. It’s a type of arteriovenous malformation (AVM) that occurs in the dura mater, which is the thick layer of tissue that protects your brain and spinal cord. Normally, tiny blood vessels (capillaries) sit between your arteries and veins to deliver oxygen and nutrients. A DAVF bypasses these capillaries, creating a direct link that can cause high pressure in the veins.
Managing a DAVF requires a highly coordinated team of neurosurgeons, neuroradiologists, interventional radiologists, and vascular specialists. At Penn Medicine, our cerebrovascular disease care specialists have expertise in treating rare and complex disorders like DAVF that other providers rarely see. This mean they know your condition well and can anticipate your needs.
How a DAVF can affect you
Often, dural arteriovenous fistulas don’t cause symptoms. For some people, a stroke is the first sign that something is wrong.
DAVFs in the brain may cause:
- Dementia or confusion
- Headaches
- Trouble with coordination or walking
- Nausea and vomiting
- Pain, numbness, weakness, or paralysis of the face
- Seizures
- Speech problems
- Weakness on one side of the body
Increased blood flow in certain areas of the brain can also lead to more specific symptoms, like:
- Bulging, swollen eye and double vision
- Heartbeat sound behind the ear (pulsatile tinnitus)
DAVFs in the spine usually develop slowly and worsen over time. The symptoms may include:
- Lower back pain
- Numbness or weakness in the legs
- Pain that radiates down one or both legs
- Trouble controlling the bladder or bowels
- Erectile dysfunction
Why dural arteriovenous fistulas develop
Most of the time, doctors are not sure what causes DAVFs. Some possible causes include:
- Infection
- Narrowing or blockage in the venous network of the brain
- Past head trauma
- Previous brain surgery
Testing for dural arteriovenous fistulas
Diagnosing a dural arteriovenous fistula usually involves imaging tests that look at the blood vessels in the brain or spine. These tests help your provider see where the abnormal connection is and how blood is flowing.
The results may be reviewed using grading systems like the Borden or Cognard methods. These systems help estimate the risk of bleeding. DAVFs can range from low risk and unlikely to cause harm (benign) to higher-risk forms that are more likely to hemorrhage.
Treatment options for DAVF
Our treatment plan depends on your symptoms, overall health, and risk of bleeding. If you have a low-grade DAVF, your provider may recommend close monitoring over time. Some people never need treatment.
Higher-risk DAVFs usually require surgical treatment to disconnect the abnormal artery-to-vein connection. Many can be treated with minimally invasive or noninvasive approaches.
Treatment for dural arteriovenous fistula at Penn Medicine
Your treatment will depend on your symptoms, overall health and risk of hemorrhage. If you have a low grade, benign DAVF, your doctor may opt to observe you over time. You may never need treatment.
Higher-risk DAVFs usually require surgical treatment to disconnect the arteriovenous connection. Our cerebral disease specialists offer the most advanced treatments available today, including:
- Endovascular embolization: This is a minimally invasive procedure. Your doctor inserts a catheter into a blood vessel and guides it to the DAVF. Your doctor may inject different types of materials, such as metal coils or glue, to block the fistula.
- Microsurgery: This is usually an option if endovascular treatments are not possible or have failed. The surgeon removes a section of the skull and uses a surgical microscope and specialized tools to disconnect the DAVF. We use imaging during surgery to make sure we completely disconnect the fistula. This helps prevent the need for additional operations.
- Radiosurgery: Doctors use this technique for less severe DAVFs. It is also an option for people who cannot undergo surgery or if endovascular or microsurgical procedures were not effective. Radiosurgery aims precise beams of radiation at the DAVF. The radiation damages the blood vessels which deteriorate and close over time.