Chapters authored
Experimental and Numerical Study of the Flow Dynamics in Treatment Approaches for Aortic Arch Aneurysms
Aortic arch aneurysm is a complex aortic pathology which affects one or more aortic arch vessels. In this chapter, we explore the hemodynamic behavior of the aortic arch in aneurysmatic and treated cases with three currently available treatment approaches: surgery graft, hybrid stent‐graft and chimney stent‐graft. The analysis included time‐dependent experimental and numerical models of aneurysmatic arch and of the surgery, hybrid and chimney endovascular techniques. Dimensions of the models are based on typical anatomy, and boundary conditions are based on typical physiological flow. Flexible and transparent experimental models were used on a mock circulation in vitro experimental system to allow both visualization and time‐dependent flow and pressure measurements. The simulations used computational fluid dynamics (CFD) methods to delineate the time‐dependent flow dynamics in the four geometric models. Results of velocity vectors, flow patterns, pressure and wall shear stress distributions are presented. Both the numerical and experimental results agree on the poor hemodynamics of the aortic arch aneurysm and present the hemodynamic advantages of the surgery technique, implying the possible advantage of fenestrated stent‐graft for the aortic arch. Out of the two minimally invasive procedures, the hybrid procedure clearly exhibits better hemodynamic performances. The chimney graft technique is based on off‐the‐shelf devices; thus, it is low in cost and requires less pre‐operation preparations. However, it is associated with higher risks for complications, such as endoleaks and stroke. This chapter may give some insight into the hemodynamic characteristics of the different procedures.
Part of the book: Aortic Aneurysm