Experimental Determination of the Mechanical and Biological Properties of Carotid Artery Plaques

Atherosclerosis is a cardiovascular disease that occurs within the walls of arteries and can result in a reduction of the lumen diameter. This reduction can cause a decrease in blood flow to the brain which can lead to a stroke event. Carotid angioplasty stenting (CAS) is a minimally invasive surgical treatment for stroke prevention and has been found to show equivalency to the highly invasive open artery repair which is a more commonly used surgical technique (Brott et al. 2010). Development in the design of stent and angioplasty devices is necessary for the continuous improvement of minimally invasive treatments of carotid artery disease. However, a major concern with regard to this treatment is the rupture of the plaque due to the almost instantaneous inflation of the stent device. To further improve the design of these devices a better understanding of the mechanical behaviour and failure of the plaque during minimally invasive treatment in the circumferential direction is required. A limited amount of data exists regarding the mechanical behaviour of atherosclerotic plaques under physiological conditions. Studies undertaken by Maher et al. (2009) and Teng et al. (2009) have tested the tensile properties of the plaque in the circumferential direction but these studies employed unphysiological strain rates which limit the true representation of the global properties of the plaque. This current study aims to biologically and mechanically characterise the whole plaque tissue and to determine if a correlation exists between the mechanical behaviour and the pre-operatively identified biological content of the plaque.