Viscoelastic Characterization of Dacron Graft and Aortic Tissue

Abstract

We present the elastic and viscoelastic characterization of aortic tissue and a synthetic material used for the fabrication of artificial vessels (Dacron). Using biaxial, high deformation and oscillating mechanical testing protocols, we assessed the hyperelastic and viscoelastic properties of both aortic tissue and Dacron. Energy loss is a viscous measure of energy absorbed by a material during deformation. It provides information of the materials time dependence and capacity to dissipate energy. Investigation of the correlation between smooth muscle cell (SMC) content and energy loss within healthy and aneurysmal aortic tissue was carried out via biaxial tensile testing of aortic tissue samples. The results of aortic tissue energy loss investigation show that an acceptable correlation exists between the presence of SMCs and the magnitude of energy loss. In addition, our data suggests that the condition and organization of SMCs may affect the viscous behaviour of tissue, instead of their mere presence. The results of the high deformation and oscillating mechanical testing show significant differences between the biological and the synthetic materials. Histologic examination of selected samples revealed healthy tissue was characterized by higher elastin content, 45.3±2.07% vs. 39.78±1.84%. Aneurysmal tissue was found to have greater SMC content in comparison to healthy tissue.