Modeling of Rheological Characteristics of Blood in Coronary Artery with Stenosis

Abstract

Introduction. This paper describes a pilot study that considers the modeling of blood flow in a straight vessel with stenosis in the approximations of a continuous medium with a constant viscosity and with a viscosity that depends on blood flow parameters — pressure in the vessel and velocity. This model describes hemodynamics in large arteries with stenoses. Most of the works devoted to the modeling of blood flow in vessels consider blood as a homogeneous fluid, the viscosity coefficient of which does not depend on velocity and pressure. This assumption simplifies the procedure of mathematical modeling of the movement of blood through the vessel, but does not fully correspond to the data of modern studies of the viscous properties of blood. The aim of the study — to demonstrate the essential influence of rheological processes in the blood on the flow characteristics in arteries with stenosis. Materials and methods. To simulate hemodynamics, a straight fragment of a vessel with stiff walls and ideal stenosis was considered. Hemodynamic flows were simulated using the Navier–Stokes model for an incompressible fluid. Hemodynamic flows were modeled using the Navier–Stokes model for an incompressible fluid, and the dependence of blood viscosity on the speed of its movement through the vessel and pressure in it was taken into account using the Carro equation. Results. It was found that the blood rheological processes significantly affect the physical properties of the medium and, consequently, hemodynamics. Discussion. The obtained characteristics of velocities, local viscosity and shear stresses, in contrast to previous studies, show that the heterogeneous composition of blood and the mechanics of microscopic processes significantly affect hemodynamics in vessels with stenoses. Good agreement of the obtained results with modern hemorheological theories is shown. Conclusions. Blood rheology should be taken into account when analyzing the hemodynamic significance of stenosis and the choice of treatment tactics.

Funding. The study was supported by the State Assignment of the Russian Ministry of Health (No. 121032200048-1). The research was supported by RSF (No. 22-71-10071).