Tensile property of atheromatous plaque and an analysis of stress in atherosclerotic wall

To know the contribution of blood pressure induced stress to the progression of atherosclerosis and the rupture of atheroma, cross-sectional distributions of stresses in atherosclerotic walls were calculated by finite element method, using stress-strain data of aortic walls and atherosclerotic plaques obtained from hypercholesterolemic rabbits. In the aortic wall attached by a local plaque, circumferential tensile stress was maximal in the wall near plaque edge, and the stress value was very high compared to the tensile strength of wall media. This local stress concentration may be a contributing factor to the progression of atherosclerotic disease. In the aortic wall uniformly lined with atheroma, circumferential stress was high in the innermost layer of atheroma, and its magnitude was comparable to the tensile strength of plaque. Stress gradient at the interface between atheroma and wall was also high. These results indicate a possibility of rupture of atheroma near the intraluminal surface of atheroma or at the junction of atheroma with wall intima.