Theoretical approach on vein graft survival : A review

Abstract

Fluid shear stress and mechanical wall stress may play a role in the formation of early atherosclerotic lesion, but these quantities are difficult to in measure in vivo. In this paper we numerically stimulate flow in a straight, inherent curvature and tapered tubes using a coordinate mapping of the Navier-Stokes equations. Most vein grafts are tapered, with variable diameter along their length. Straight, inherent curvature and tapered have been proposed for use as vein bypass graft. Internal diameter is a strong predictor of patency for prolonging vein bypass graft survival. Previous internal diameter observations were clinically applied, however only a little basis of hemodynamic theory. The contribution of diameter to vein graft resistance will be examined, with the concept longitudinal impedance (ZL). Those quantities that are outflow dependent, including pressure gradient, flow, velocity, shear stress, and resistance will be determined by computational program. This is enables estimation of the minimal graft diameter allowable for given length, as well as the possible hydraulic consequences of the inevitable taper that accompany upper limb vein bypass grafts.