title: Haemodynamical stress in mouse aortic arch with atherosclerotic plaques: Preliminary study of plaque progression.
abstract: Atherosclerotic plaques develop at particular sites in the arterial tree, and this regional localisation depends largely on haemodynamic parameters (such as wall shear stress; WSS) as described in the literature. Plaque rupture can result in heart attack or stroke and hence understanding the development and vulnerability of atherosclerotic plaques is critically important. The purpose of this study is to characterise the haemodynamics of blood flow in the mouse aortic arch using numerical modelling. The geometries are digitalised from synchrotron imaging and realistic pulsatile blood flow is considered under rigid wall assumptions. Two cases are considered; arteries with and without plaque. Mice that are fed under fat diet present plaques in the aortic arch whose size is dependent on the number of weeks under the diet. The plaque distribution in the region is however relatively constant through the different samples. This result underlines the influence of the geometry and consequently of the wall shear stresses for plaque formation with plaques growing in region of relative low shear stresses. A discussion of the flow field in real geometry in the presence and absence of plaques is conducted. The presence of plaques was shown to alter the blood flow and hence WSS distribution, with regions of localised high WSS, mainly on the wall of the brachiocephalic artery where luminal narrowing is most pronounced. In addition, arch plaques are shown to induce recirculation in the blood flow, a phenomenon with potential influence on the progression of the plaques. The oscillatory shear index and the relative residence time have been calculated on the geometry with plaques to show the presence of this recirculation in the arch, an approach that may be useful for future studies on plaque progression.
authors.affiliation: Department of Mechanical and Aerospace Engineering, Division of Biological Engineering, Monash University, Victoria 3800, Australia.
authors.forename: P
authors.initials: P
authors.lastname: Assemat
authors.affiliation: Monash Biomedical Imaging, Monash University, Victoria 3800, Australia ; Australian Synchrotron, 800 Blackburn Rd, Clayton, Victoria 3168, Australia.
authors.forename: K K
authors.initials: KK
authors.lastname: Siu
authors.affiliation: School of Medicine (Optometry), Deakin University, Waurn Ponds, Victoria 3228, Australia ; Department of Anatomy and Developmental Biology, Monash University, Clayton, Victoria 3880, Australia ; Baker IDI Heart and Diabetes Institute, 75 Commercial Rd, Melbourne, Victoria 3004, Australia.
authors.forename: J A
authors.initials: JA
authors.lastname: Armitage
authors.affiliation: School of Medicine (Optometry), Deakin University, Waurn Ponds, Victoria 3228, Australia ; Department of Anatomy and Developmental Biology, Monash University, Clayton, Victoria 3880, Australia ; Baker IDI Heart and Diabetes Institute, 75 Commercial Rd, Melbourne, Victoria 3004, Australia.
authors.forename: S N
authors.initials: SN
authors.lastname: Hokke
authors.affiliation: Department of Anatomy and Developmental Biology, Monash University, Clayton, Victoria 3880, Australia.
authors.forename: A
authors.initials: A
authors.lastname: Dart
authors.affiliation: Department of Anatomy and Developmental Biology, Monash University, Clayton, Victoria 3880, Australia.
authors.forename: J
authors.initials: J
authors.lastname: Chin-Dusting
authors.affiliation: Department of Mechanical and Aerospace Engineering, Division of Biological Engineering, Monash University, Victoria 3800, Australia.
authors.forename: K
authors.initials: K
authors.lastname: Hourigan
keywords: Mechanical effects; Oscillating flow; Synchrotron imaging; Wall shear stress