Study of Pulsatile Non-Newtonian Blood Flow Through Abdominal Aorta and Renal Arteries Incorporating Fluid- Structure Interaction

Background: The interaction between the blood and the vessel wall is of great clinical interest in studying cardiovascular diseases, the major causes of death in developed countries. Objective: To understand the effects of incorporating fluid-structure interaction into the simulation of blood flow through an anatomically realistic model of abdominal aorta and renal arteries reconstructed from CT images. Methods: The fluid is assumed to be incompressible and non-Newtonian and the vessel wall is set to have isotropic elastic properties. The blood flow is assumed to be periodic; therefore, a real pulsatile flow velocity in the entrance of the abdominal aorta of a healthy adult is measured via laser Doppler anemometry and used in this study. The effects of wall flexibility, both rigid and compliant models were also simulated. Results: Comparison of the rigid model with compliant model reveals that velocity and pressure drop in flexible arteries is less than those in rigid arteries. As wall shear stress plays an important role in the function of the cardiovascular system as it has immediate effect on the endothelial histology, the wall shear stress was analyzed; the rigid model wall shear stress magnitude was higher than that in the compliant model. It was also observed that the peak values of wall shear stress in this study were not high enough to be able to damage and strip the endothelial cells. Displacements of vessel walls were also studied; it was found that the wall displacement during the systole was higher than the diastole. Conclusion: Incorporating fluid-structure interaction and considering vessel wall deformations in studying blood flow through arteries have notable effects on blood flow characteristics.