Dural Arteriovenous Fistula - Classification

Classification

The Borden Classification of dural arteriovenous malformations or fistulas, groups into three types based upon their venous drainage:

1. Type I: dural arterial supply drains anterograde into venous sinus.
2. Type II: dural arterial supply drains into venous sinus. High pressure in sinus results in both anterograde drainage and retrograde drainage via subarachnoid veins.
3. Type III: dural arterial supply drains retrograde into subarachnoid veins.