Flow Patterns In Helical-type Graft: Biomedical Applications

The long-term success of arterial bypass surgery is often limited by the progression of intimal hyperplasia at the anastomosis between the graft and the native artery. The experimental models were manufactured from glass tubing with a constant internal diameter of 8 mm, fashioned into a straight configuration and helical configuration. The aim of this study was to determine the three-dimensional flow structures in the proximal anastomosis under pulsatile flow conditions and to establish the significant differences between the straight and helical graft. In the anastomosis domain, a stable region of recirculation is observed near the occluded end of the artery, which forces the flow to move into the perfused host coronary artery. A comparison between experimentally measured velocity patterns in straight and helical grafts confirms the robust nature of the secondary flows in the helical geometry. The helical configuration promotes the mixing effect of vortex motion such that the particles are mixed into the blood stream in the junction area.