A Comparative Assessment of the Effects of Single and Multiple Stenoses on Hemodynamics of an Idealised Artery Model

The present study examines the effect of single and double stenoses of moderate severity on the hemodynamics of an idealized arterial model using the immersed boundary method-based in-house Computational Fluid Dynamics (CFD) code. A realistic physiological pulsatile velocity waveform with parabolic variation in space is adopted as an inlet boundary condition in a straight arterial tube. Blood is regarded as a Newtonian fluid and the flow as laminar and incompressible. The degree of stenosis (DS) is defined by the obstructed cross-sectional area. The velocity contours show that single or double stenoses with moderate severity cause additional flow disruptions downstream of the stenoses. Time-Averaged Wall Shear Stress (TAWSS) is low and Oscillatory Shear Index (OSI) is high in the post-stenotic regions, which could lead to the progression of atherosclerosis. The areas with high TAWSS, such as throat of the stenosis, are potential sites for thrombus formation. Moreover, a very small region of low TAWSS and high OSI is seen at the starting of the proximal stenosis, which implies that plaque deposition can take place in the upstream region in addition to its progression in the downstream regions.