Development of a Quantitative Mechanical Test of Atherosclerotic Plaque Stability

摘要

Atherosclerotic plaque rupture is the main cause of myocardial infarction, coronary thrombosis and stroke. Current clinical observations suggest that an advanced plaque features a thin, collagen-rich fibrous cap infiltrated by macrophages, overlying a large lipid core rich in lipid-laden macrophages. However, due to relatively poor understanding of mechanisms associated with plaque rupture, there is no quantitative standard for plaque stability estimation.rnPrevious studies of plaque rupture mechanisms have mainly focused on the mechanical properties of the plaque itself and the forces acting on the luminal surface of the plaque. Clinical autopsy and theoretical model studies have shown that the shoulder region, where a plaque joins the surrounding vascular wall, is rupture-prone [1, 2]. Therefore, the adhesive strength of the bond between the plaque and the vascular wall is a promising candidate for quantitative plaque stability estimation. Peeling tests have been widely used in examining interlaminar adhesive strength of various biological materials [3, 4]. Local energy release rate in our plaque peeling test is related to fracture energy required to delaminate a unit area of a plaque from the underlying Internal Elastic Lamina (IEL), which reflects the local adhesive strength of the plaque-IEL interface. We hypothesize that local energy release rate during delamination provides a means to quantitatively evaluate plaque stability.