The Impact of Patches on Blood Flow Disorders In Carotid Artery

Abstract

The atherosclerotic plaques are surgically removed by endarterectomy of the common and internal carotid artery wall, removal of lesions, and suturing the artery again. To avoid arterial lumen stenosis, sewing a patch in the incision area is indicated, which will cause a slight expansion of the flow lumen. The channel expansion causes a positive tension gradient, enhancing separation of the parietal layer and occurrence of whirlpools. The latter may cause plaque redeposition. The selection of the patch size is not described in detail in the literature and is based on the surgeon’s experience and intuition. The purpose of the studies is to determine the maximum patch width per surgical incision at which no flow separation will occur. To determine the geometry of the channel with a patch sewn in, an equation was determined to reflect the course of the arterial wall curves by math functions. The artery radius, the maximum expansion radius, and the length of the patch sewn in have been assumed as the input parameters that define the boundary conditions necessary for the determination of polynomial coefficients. By a gradual increase of the maximum radius, a geometry group was determined, which was the starting point for numerical simulations. The simulations were made with the use of Fluent. The increasing of the maximum radius was continued until the separation of the parietal layer was detected and whirlpools occurred. The results showed that when the maximum radius is 30% greater in relation to the arterial radius, whirlpools occur, which in consequence may lead to plaque redeposition.