What Are Dural Arteriovenous Fistulas (DAVF)?
Dural arteriovenous fistulas (DAVFs) are abnormal connections between arteries and veins within the covering of the brain (dura). Unlike brain arteriovenous malformations (AVMs), these abnormal vessel connections develop in adults; DAVF patients are not typically born with these vessel abnormalities. DAVFs lead to increased pressure in brain veins which can result in a variety of symptoms.
The cerebrovascular neurosurgeons at Baylor Medicine specialize in the diagnosis and treatment of DAVFs. Each patient is different and our doctors provide expertise managing this disorder.
- Tinnitus - Many patients with DAVFs near the ear describe a whooshing sound, and others describe it as a high-pitched ringing sound.
- Eye symptoms - Some patients develop pain behind the eye, eye redness, eye swelling, decreased vision and even double vision when the abnormal artery-vein connection is near the eye.
- Brain hemorrhage - Certain patients can develop bleeding into the brain. Patients at risk are those who have a DAVF that drains abnormal, high-pressure artery blood flow directly into veins of the brain. This is a dangerous situation known as cortical venous drainage (CVD). Symptoms suggestive of brain hemorrhage include sudden-onset headache, nausea, vomiting, decreased level of consciousness, weakness, numbness and trouble with speech.
- Seizures - Patients with CVD can also develop seizures.
- Cognitive decline - Patients with longstanding, untreated DAVFs can develop cognitive decline with symptoms similar to dementia.
If an arteriovenous fistula is suspected, it is important to make a diagnosis and consult with a specialist quickly to prevent worsening of the disease. Based on the patient's symptoms, the physician may order one or all of these tests. All of these tests are often needed before making a decision about treatment.
- CT scans
- Magnetic resonance imaging (MRI)
- Cerebral angiogram
Treatment decisions will be tailored to the AVF’s location, presence or absence of CVD, severity and nature of symptoms, and the risk involved in treatment. Treatment options for brain AVFs include:
- Observation - When a patient has an AVF without CVD, and the symptoms are mild, observation is often the recommended choice.
- Endovascular Embolization - This procedure entails passing a small catheter from a blood vessel in the groin up into the AVF, where glue or other material is injected into the abnormal vessel (Figure 1). This is the most common treatment of DAVF and is often curative.
- Surgery - Open surgery and direct ligation/resection of the AVF is offered for a small subset of AVFs when embolization is not safe or curative.
- Radiosurgery - When both embolization and surgery fail, radiosurgery, a technique that involves precisely focusing radiation beams onto the AVF, can cause the AVF to shrink over time.