Modelling of blood flow in coronary stented arteries

Atherosclerosis is the underlying cause of the majority of clinical cardiovascular events in the developed societies. Atherosclerotic lesions in coronary arteries are usually treated with percutaneous procedures which consist of placing wire mesh tubular structures, known as stents, into the diseased vessel. The main clinical complication is the in-stent restenosis (ISR) which is the local reduction in lumen size as a result of neointimal hyperplasia. Mechanisms and causes of ISR are not fully understood; in addition to stent design, vascular injury caused by device implantation, hemodynamic alterations induced by its presence can be associated with neointimal hyperplasia. Therefore, the study of the fluid dynamics of stented coronary arteries is of extreme importance for a better comprehension of the mechanisms involved in ISR. In the present chapter a review of the works on the hemodynamics of stented coronary arteries is given, focusing in particular on the computational fluid dynamics (CFD) models. Indeed, CFD allows the investigation of local hemodynamics at a level of detail not always accessible with experimental techniques, calculating fluid flow variables (e.g. wall shear stress) that can be used as indicators to predict sites where neointimal hyperplasia is excessive. Application of CFD to idealized, population-specific and patient-specific coronary stented models is outlined as well