Plaque Ulceration Is Associated With High Stear Stress in Stenotic Carotid Bifurcations

Cerebrovascular events are related to atherosclerotic disease in the carotid arteries and they are often caused by rupture of an atherosclerotic plaque. Rupture-prone, or vulnerable, plaques are characterized by their specific morphology and composition: a large lipid pool covered by a thin fibrous cap infiltrated by macrophages and expansive remodeling. The strength of the cap of a vulnerable plaque is determined by the material properties of the cap and its thickness. Plaque ruptures are often observed at the upstream region of the plaque [1], were the wall shear stress (WSS) is considered to be highest. High WSS is known for its influence on many processes affecting, among others, tissue regression [2]. Therefore, high shear stress induced cap regression might contribute to cap thinning, thus enhancing plaque vulnerability, and eventually leading to cap rupture [3,4]. Here we present the first results of a new approach to study the relationship between WSS and the location of ulcerations in severely stenotic carotid bifurcations by using computational fluid dynamics and computed tomography.