In Vitro Modelling of Aortic Dissection for Bare-Metal Stent Intervention

Type-A aortic dissection (AD) is associated with a high mortality rate of over 93% in 24 h after vascular events. In the elderly, there is often a limitation for surgical treatment. Therefore, there is an increasing need for minimally invasive treatment methods. The study aims to develop an in vitro circulatory model reproducing the haemodynamics of AD to investigate the therapeutic effect of a newly designed bare-metal-stent on the amelioration of the lesion. In this study, we conducted in vivo experiment in order to measure basic data on the anatomical morphology and haemodynamics of AD. Based on these results, we have developed a new in vitro elastic dissection model that provides indexes of design features for stent development. This model was made of silicone, which could be visualised by echocardiography imaging, and had a layered structure similar to that of a natural aorta. The in vivo experiments confirmed that the stenting had compressed the false lumen and reduced blood flow. The in vitro model visualized the haemodynamics of aortic dissection under pulsatile flow conditions and showed that the false lumen (FL) pressure was higher than the true lumen (TL) pressure. Consequently, we were able to visualize the haemodynamics of aortic dissection and develop a model that can evaluate the pressure exerted by the stent on the FL under pulsatile flow conditions. In the future, we will be able to observe more detailed haemodynamics when stents are implanted in this model representing several types of Type A AD clinical cases.