Dural Arteriovenous Fistulae (DAVF) are rare, abnormal direct connections (fistula) betweenarteries and veins in a protective membrane on the outer layer of the brain and spine, called the dura.
These abnormal blood vessels divert blood from the normal paths. If the volume of diverted blood flow is large, tissue downstream may not receive an adequate blood and oxygen supply. An unusually heavy blood flow also can lead to aneurysms or ruptures in the veins.
This condition can be caused by:
- Head trauma
- Infection
- Surgery
- Blood clots in the brain, called thrombosis
- Congenital birth defect
Although symptoms of dural arteriovenous fistulae (DAVF) may vary, some of the more common include:
- An unusual ringing or humming in the ears
- Headaches
- Visual problems
- Stroke-like symptoms
Treatment for dural arteriovenous fistulae (DAVF) depends on the blood vessels involved. Endovascular techniques, which are minimally invasive procedures that are performed through the blood vessels, have been developed to safely treat DAVFs.
One approach used for treatment is embolization, a non-surgical, minimally-invasive procedure that reduces blood flow to the DAVF by obstructing surrounding blood vessels. During this procedure, the DAVF is filled with specially designed coils, glues or spheres that plug the vessels.
Some fistulas can’t be completely blocked with embolization and may require surgery to disconnect or close them. In some cases, doctors may try to close the fistula with what’s called stereotactic radiosurgery or the Gamma Knife.