Dural Arteriovenous Fistulae (DAVF's) are abnormal connections between arteries and veins in the brain. They are acquired, and often develop with age. While they can cause symptoms of tinnitus and headache, a subset of DAVF's can cause progressive neurological decline or potentially fatal cerebral hemorrhage. Endovascular embolization can be used to treat dangerous DAVF's or those DAVF's that cause persistent distressing symptoms.
Cranial DAVF’s are incompletely understood lesions characterized by abnormal connections between arteries of the head and the veins that drain the brain. Many DAVF’s will be completely asymptomatic, or only mildly symptomatic. However, when the fistula is large enough, there will be abnormal reversal of flow in the veins that drain the brain.
When the flow is reversed in the cerebral veins, the risk of hemorrhage increases dramatically. Even in patients without hemorrhage, there is a high rate of neurological defects, which are thought to be due to the abnormally increased venous pressure in the vein.
Some mild DAVF’s may resolve spontaneously, or, after evaluation by an experienced neurointerventionalist, may be managed conservatively. However, given the high rate of hemorrhage for severe DAVF’s, conservative treatment is not recommended except for mild cases.
For patients with severe fistulae, or fistulae with symptoms that the patient cannot tolerate, we can perform an endovascular embolization with a liquid embolic agent. A catheter is advanced into the arteries supplying the DAVF. A liquid embolic agent is then used to obliterate the feeding arteries. Sometimes, arterial embolization is combined with venous embolization to close the fistula from the venous side as well.
Often, if the fistula is not occluded during embolization, surgery may be recommended; however, the success rate for treatment at MMC is high, and rarely requires surgery.