Numerical study of a complete anastomosis model for the coronary artery bypass

Intimal hyperplasia (IH) has been cited as a major cause of vascular graft failure, which is associated with the hemodynamic conditions [H.S. Bassiouny, S. White, S. Glagov, E. Choi, D.P. Giddens, C.K. Zarins, J. Vasc. Surg. 15 (1992) 708-717; D.A. Vorp, ASAIO J. 43 (3) (1997) 237-238]. Most of the earlier studies were concentrated on the distal anastomosis; therefore, in this study, computational methods were used to describe the blood motion in a complete anastomosis model, which included both the proximal and the distal anastomosis parts. Under the typical physiological condition, high gradients of velocity and wall shear stress were found to focus on the distal part. Since hemodynamic conditions influence the response of vascular endothelial cell, the flow field may affect IH formation and thereby the long-term graft patency rate. As surgeons have some control over the anastomosis geometry, smaller grafting angle and smooth geometry may aid the improvement of graft patency rate.