Correlation of Laser-Doppler-Velocity Measurements and Endothelial Cell Shape in a Stenosed Dog Aorta
Apart from chemical factors, hemodynamics play a major role in atherosclerosis and aging. It has been suggested that vascular geometry may affect the atherogenic process by its influence on the hemodynamic environment which the intima is exposed to.1,2 Rodkiewicz3 demonstrated very clearly the shear stress on the wall at flow separation and stagnation points. Several flow studies were done in artery models to find out the influence of hemodynamic forces on the vessel wall and on the blood cells; only a few shall be mentioned here.4,5,6,7,8 The vessel wall is very resistant against pressure perpendicular to the wall. Pressure on the vessel wall is usually between 10,000 to 20,000 N/m2. These forces are compensated by the elastin or collagen fibers in the wall. However, forces which are tangential-shear stresses attack the endothelial cells and their resistance is much less. At shear stresses from 20 to 40 N/m2 the endothelial cells are sheared away. This can lead to an injury of the inside vessel wall. Usually, the shear stresses on the endothelial cells are about 1–2 N/m2. Thus, the effect of such forces upon endothelial cells is therefore of great interest.
KeywordsWall Shear Stress Pulsatile Flow Shape Index Stenosed Area Model Stenosis
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