Computer Simulation of the Adaptive Changes in Vascular Geometry Caused by the Development of Atherosclerotic Lesions(<Special Issue>Bioengineering of Biological and Medical Materials)

To investigate the effects of hemodynamic factors on the development of atherosclerosis and intimal hyperplasia, we carried out a computer simulation of the adaptive changes in the thickness of the wall of a human coronary artery with a multiple bend. This was done by assuming that only the arterial wall where wall shear stress (WSS) is lower than a certain threshold value increases its thickness, and shifting the luminal surface of the vessel step by step in the direction normal to the wall based on the value of WSS obtained by the calculation of blood flow through the artery under conditions of a steady flow. It was found that thickening of the vessel wall occurred and progressed at the inner wall of curved segments where WSS were low in the initial state. However, the final thickness of the wall at the completion of adaptive changes was not determined by the value of WSS in the initial state, but was determined as a result of the interaction between the change in vascular geometry caused by the thickening of the vessel wall and the flow affected by it.