A dural arteriovenous fistula is an abnormal direct connection (fistula) between a meningeal artery and a meningeal vein or dural venous sinus.
There are two types of classification can be observed there as follows: I. Borden Classification II. Cognard Classification There are further divided in to sub categories like: I. Borden Classification a. Type I: dural arterial supply drains anterograde into venous sinus. b. Type II: dural arterial supply drains into venous sinus.