Inelasticity of Human Carotid Atherosclerotic Plaque
- 387 Downloads
Little mechanical test data exists regarding the inelastic behavior of atherosclerotic plaques. As a result finite element (FE) models of stenting procedures commonly use hyperelastic material models to describe the soft tissue response thus limiting the accuracy of the model to the expansion stage of stent implantation and leave them unable to predict the lumen gain. In this study, cyclic mechanical tests were performed to characterize the inelastic behavior of fresh human carotid atherosclerotic plaque tissue due to radial compressive loading. Plaques were classified clinically as either mixed (M), calcified (Ca), or echolucent (E). An approximately linear increase in the plastic deformation was observed with increases in the peak applied strain for all plaque types. While calcified plaques generally appeared stiffest, it was observed that the clinical classification of plaques had no significant effect on the magnitude of permanent deformation on unloading. The test data was characterized using a constitutive model that accounts for both permanent deformation and stress softening to describe the compressive plaque behavior on unloading. Material constants are reported for individual plaques as well as mean values for each plaque classification. This data can be considered as a first step in characterizing the inelastic behavior of atherosclerotic plaques and could be used in combination with future mechanical data to improve the predictive capabilities of FE models of angioplasty and stenting procedures particularly in relation to lumen gain.
KeywordsMechanical properties Plastic deformation Permanent deformation Stress softening Plaque Constitutive model
This material is based on works supported by the Science Foundation Ireland under Grant No. 07/RFP/ENMF660.
- 3.Barrett, S. R., M. P. Sutcliffe, S. Howarth, Z. Y. Li, and J. H. Gillard. Experimental measurement of the mechanical properties of carotid atherothrombotic plaque fibrous cap. J. Biomech. 41(9):1995–2002, 2009.Google Scholar
- 5.Chua, S. N. D., B. J. MacDonald, and M. S. J. Hashmi. Finite element simulation of slotted tube (stent) with the presence of plaque and artery by balloon expansion. J. Mater. Process. Technol. 155–156:1772–1779, 2004.Google Scholar
- 17.Holzapfel, G. A. Nonlinear Solid Mechanics. New York: John Wiley & Sons, 2000.Google Scholar
- 23.Lee, R. T., S. G. Richardson, H. M. Loree, A. J. Grodinsky, S. A. Gharib, F. J. Schoen, and N. Pandian. Prediction of mechanical properties of human atherosclerotic tissue by high-frequency intravascular ultrasound imaging. An in vitro study. Arterioscl. Thromb. Vasc. Biol. 12:1–5, 1992.CrossRefGoogle Scholar
- 29.Miehe, C. Discontinuous and continuous damage evolution in Ogden-type large-strain elastic materials. Eur. J. Mech. A Solids 14:697–720, 1995.Google Scholar
- 31.Mortier, P., G. A. Holzapfel, M. De Beule, D. Van Loo, Y. Taeymans, P. Segers, P. Verdonck, and B. Verhegghe. A novel simulation strategy for stent insertion and deployment in curved coronary bifurcations: comparison of three drug-eluting stents. Ann. Biomed. Eng. 38:88–99, 2010.PubMedCrossRefGoogle Scholar
- 47.Woo, C., W. Kinm, and J. Kwon. A study on the material properties and fatigue life prediction of natural rubber component. Mater. Sci. Eng. A 483–484:376–381, 2008.Google Scholar