Recognition of dural to pial supply in high-grade dural arteriovenous fistula: A technical note.

High-grade dural arteriovenous fistulas (DAVFs) are known to demonstrate classical dural supply and can demonstrate pre-existing dural supply and 'pure' arterial supply from pial branches. The latter two are examples of congenital versus acquired pial to dural shunting, respectively. We describe the recognition of dural to pial supply during combined transarterial and transvenous embolization of a high-grade DAVF with holocephalic venous reflux, stressing the importance of careful assessment of this condition with micro catheter injections.