Application Of Particle Image Velocimetry For The Anatomical Comparison Of Haemodynamics In Healthy And Treated Aortas.

Abstract

The leading cause of mortality and morbidity globally is cardiovascular disease (CVD). CVD can present in the thoracic aorta as atherosclerosis, an aneurysm or a dissection, which can be related to certain fluid mechanics metrics. This study investigates the fluid flow profiles within a healthy and a branched endovascular graft-treated rigid phantom, manufactured from Sylgard 184, to determine the effect geometry has on the resulting fluid mechanics and the subsequent biological processes. Planar particle image velocimetry data was recorded to visualise steady flow conditions at Reynolds numbers 4500 (peak), 3400 (mean), and −225 (reverse). Evaluation of anatomical features affecting the flow fields, concluded that the tapering of the healthy thoracic aorta naturally aids in the prevention of low flow on the inner arch wall more effectively than the untapered graft-treated model. Focus on the aortic branches demonstrated the angle of the aortic branches in relation to the aortic arch, highly affects the regions of low and high blood flow present within each branch. However, due to the biological response (or lack of) associated with a cellular boundary and synthetic material, the haemodynamic changes in the aortic arch and branches have different challenges. Therefore, direct replication of a healthy geometry is not necessarily optimal for the design of an endovascular graft.