Dural arteriovenous fistulae (DAVF) are rare, abnormal connections between arteries 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. This condition can be caused by head trauma, infection, surgery or blood clots in the brain, called thrombosis, or may be a congenital or birth defect.
An epidemiological survey of the detected DAVF cases in Japan between 1998 and 2002 was conducted. The detection rate of DAVF per 100,000 adults per year is 0.29 for DAVF. Furthermore, unlike European countries and North American countrieswhere cases of transverse-sigmoid sinus DAVF are predominantly detected, in Japan, a higher number of cases of cavernous sinus lesions are detected, indicating racial difference in the presentation of DAVF. The symptoms of dural arteriovenous fistulae (DAVF) can vary widely, depending on the location of the fistulae. Some of the common symptoms include headaches, an unusual ringing or humming in the ears may be symptom, particularly when the DAVF is near the ear. DAVFs can cause stroke-like symptoms and seizures, if they rupture. Bleeding in the brain is the most serious side effect and can cause permanent disability or death.
First step of the treatment is to obtain an entire picture of a DAVF and characterize it. Cerebral angiography (dye injection into brain arteries through a plastic tube) is the gold-standard and the most accurate way to do so. Based on the finding of cerebral angiography and the symptoms, the following options are offered Endovascular embolization or open surgery are offered. One of the most worrisome finding is so called "cortical venous reflux". This is the sign that blood flow return to the brain is compromised and associated with high risk of brain hemorrhage.