Streamlines in the end-to-side models with longitudinal or bilateral stenosis. The original model shows a vortex at the heel, arterial floor impingement and distal laminar flow. With longitudinal stenosis, a narrower anastomosis created a steeper flow angle. Conversely, bilateral stenosis generated helical flow along the lateral wall. In both 75% stenotic patterns, flow impinged on the native artery floor, leading to flow separation at the toe (red arrows).