CFD analysis of pulsatile blood flow in an atherosclerotic human artery with eccentric plaques.
Atherosclerosis is a slow vascular degeneration. It thickens the internal walls of a blood vessel locally depositing an atherosclerotic plaque. Such reduced lumen increases the resistance to blood flow. Plaques can be punctual (eccentric, here considered) or circumferential (symmetrical). Stenoses do not have a typical shape: we hypothesised here a reference geometry (trapezium) with its possible evolutions (semi-ellipse, triangle). Two criteria (Equivalent Area and Equivalent Dimensions) were then defined to compare the results among the 35 case studies numerically analysed with a Computational Fluid Dynamics code (Comsol Multiphysics 3.3). Blood was considered a Cassonian fluid with modified viscosity equation. The artery was cylindrical, rigid and straight, interested by a pulsatile blood flow. Among the variables: shape and dimensions of the stenoses; number of stenoses (single or coupled pathologies); mutual locations (3 possibilities). The main results were that the length of the consequent flow disturbance is due to the stenotic shape and height; blood flow recirculation, downstream of the pathology, is due to the slope of the stenotic walls; and the peak velocities depend on the shape and height of stenosis. The differences from case to case diminish in diastole.
Department of Agricultural Economics and Engineering, Alma Mater Studiorum-University of Bologna, Bologna 40127, Italy. giulio.lorenzini@unibo.it
Giulio
G
Lorenzini
Erminio
E
Casalena
D001158:Arteries / Q000503:physiopathology; D050197:Atherosclerosis / Q000503:physiopathology*; D003198:Computer Simulation; D006801:Humans; D011673:Pulsatile Flow; D015607:Stents