EFFECTS OF FRICTIONAL LOSSES AND PULSATILE FLOW ON THE COLLAPSE OF STENOTIC ARTERIES

High-grade stenosis can produce conditions in which the artery may col lapse. A one-dimensional numerical model of a compliant stenosis was d eveloped from the collapsible tube theory of Shapiro. The model extend s an earlier model by including the effects of frictional losses and u nsteadiness. The model was used to investigate the relative importance of several physical parameters present in the in vivo environment. Th e results indicated that collapse can occur within the stenosis. Frict ional loss was influential in reducing the magnitude of collapse. Larg e separation losses could prevent collapse outright even with low down stream resistances. However, the degree of stenosis was still the prim ary parameter governing the onset of collapse. Pulsatile solutions dem onstrated conditions that produce cyclic collapse within the stenosis. This study predicts certain physiologic conditions in which collapse of arteries may occur for high-grade stenoses.