Differences in mechanical properties between human and porcine aortic root

Recently, percutaneous aortic valve (PAV) replacement has been investigated as an endovascular alternative for the treatment of aortic stenosis. Percutaneous valve intervention requires a thorough material characterization of the human aortic root and ascending aorta for successful PAV deployment and function. Recent PAV clinical trials have been conducted on animal models under the assumption that animal tissues are closely related to human (1, 2). However, various adverse effects detected after device implantation such as device fracture, myocardial infarction, peripheral embolism, aortic injury, perivalvular leak and access site injury have been reported (3, 4). We hypothesize that the biomechanical interaction between the device and the host tissue plays an important role that determines the efficacy of the PAV treatment. Thus, there is a need obtaining the mechanical properties of the host tissues for the future analysis of device-tissue interaction. In this study, we characterized the mechanical properties of aged human aortic tissues and compared them to porcine tissues to determine whether animal studies are appropriate for the PAV trials. Our results suggest there are significant differences between porcine and human aortic tissues and the efficacy of animal models for PAV simulation should be further investigated.