Hemodynamic analysis of pulsatile blood flow in a complete bypass graft with different anastomosis angles

Abstract

The fluid flow through a bypass graft of 100% stenosed artery can substantially influence the outcome of bypass surgery. To help improve our understanding of this and related issues, unsteady flows for Newtonian/non-Newtonian fluids using Carreau’s shear thinning model are numerically simulated in an arterial bypass system with complete occluded host artery. The objective of this study is to deal with the influence of the non-Newtonian property of fluid, effect of different bypass-host artery angle θ, and flow pulsatility on flow configuration, wall shear stress (WSS), oscillatory shear index (OSI), and flow phenomena during the pulse cycle. Here we use θ= 30°, 45°, 60°, and 75° to study the effect of geometry. It is found that θ has strong influence on hemodynamic in distal femoral artery anastomoses. Results show that a bypass femoral anastomosis with a moderate θ, like θ =45° enhances its long-term performance. Also significant difference between the non-Newtonian and Newtonian pulsatile flows is revealed. This shows the necessity of using non-Newtonian model rather than Newtonian model for such flows. The unsteadiness of flow using the femoral pulsatile behavior of flow affect the dynamic behavior of the flow and shows complex flow characteristics, therefore the necessity of using unsteady analysis.