Treatment of dural arteriovenous fistulas.

The treatment of a dural arteriovenous fistula (DAVF) depends on the severity of the symptoms, its angiographic characteristics, and the risk it presents for intracranial hemorrhage. In many instances, therapy may involve a combination of more than one modality. Low-risk DAVFs, either incidental or with minimal symptoms, can be treated conservatively (observation, blood pressure control, manual carotid compressions). If the patient does not tolerate the symptoms, definite or palliative treatment can be offered. All high-risk DAVFs (Borden Grade II or III) should receive treatment because they carry a high probability of intracranial hemorrhage or neurologic deterioration. For small, well-circumscribed fistulas, radiosurgery can have excellent results, but thrombosis can occur many months after the treatment. For large DAVFs with severe symptoms (vision deterioration, ophthalmoplegia with diplopia, seizures, or neurologic deficit) or with high risk for hemorrhage (cortical venous drainage or venous varices), the first treatment option should be endovascular embolization. With the combination of modern materials and techniques, this procedure can yield a high rate of cure with minimal complications. In patients not amenable to embolization or after incomplete embolization, surgery should be considered if the DAVF is located in an easily accessible area, because of its immediate and definite results. Surgery can be facilitated by preoperative embolization of the fistula to reduce the arterial supply and minimize intraoperative bleeding. Radiosurgery can also be used adjunctively after embolization or surgery has significantly reduced the size of large DAVFs.