Enhancement of vascular graft design inspired by tissue microstructure through the combination of 3D X-ray histology and mechanical testing

According to the World Health Organization, cardiovascular diseases are the number one cause of death globally. In case of an arterial occlusion, a bypass has to be performed. Bypass surgery can be performed using autologous veins or synthetic vascular grafts. Autologous veins are limited by their availability. Important complications still remain for synthetic vascular grafts. Indeed, the still existing mismatch in mechanical properties between the currently available grafts and the native tissue is a major cause of synthetic graft failure. Specifically, the heterogeneous build-up of the native arterial wall, as well as its anisotropy, its nonlinearity and viscoelasticity lead to specific mechanical behaviour. It is very difficult to replicate both microstructure and mechanical behaviour using synthetic vascular grafts. Nowadays, the current synthetic vascular grafts still fail to replicate the unique microstructural and mechanical properties of the native arterial tissue. Therefore, consideration of both structural and mechanical properties is necessary in graft design. The aim of this PhD project is to study the microstructure of the native blood vessel using X-ray-based 3D histology. Combining 3D imaging and mechanical testing will allow studying the relationship between the vessel microstructure and its mechanical properties. This information is then used to define representative volume elements for the different layers of the vessel wall, and to design and produce new microstructure-inspired vascular grafts.