Fig. 3.

Flow changes associated with EC-IC bypass. A qualitative depiction of flow patterns in intracranial stenosis with reduction of flow velocities associated with arterial narrowing before the stenosis and acceleration of flow in the stenotic segment. Distal flow can reach critical low velocities (blue and black arrows). After bypass placement, a theoretical competitive flow introduced by the bypass on the post-stenotic arterial segment can precipitate increased turbulence, stasis of flow and thrombosis of adjacent perforators, and the stenotic segment itself