High-risk dural arteriovenous fistulae of the transverse and sigmoid sinuses.

Dural arteriovenous fistulae of the transverse and sigmoid sinuses are highly variable in symptomatology and prognosis. However, we have identified a subgroup of patients who have a high risk of hemorrhage and dementia due to severe venous overload caused by high arterial flow into the fistulae and by occlusive changes of the transverse and sigmoid sinuses. Three representative cases selected from 31 patients with dural arteriovenous fistulae of the transverse and sigmoid sinuses are presented, and 45 reported similar cases are reviewed to discuss pathophysiology and problems encountered during treatment.