title: Viscosity and haemodynamics in a late gestation rat feto-placental arterial network.
abstract: The placenta is a transient organ which develops during pregnancy to provide haemotrophic support for healthy fetal growth and development. Fundamental to its function is the healthy development of vascular trees in the feto-placental arterial network. Despite the strong association of haemodynamics with vascular remodelling mechanisms, there is a lack of computational haemodynamic data that may improve our understanding of feto-placental physiology. The aim of this work was to create a comprehensive 3D computational fluid dynamics model of a substructure of the rat feto-placental arterial network and investigate the influence of viscosity on wall shear stress (WSS). Late gestation rat feto-placental arteries were perfused with radiopaque Microfil and scanned via micro-computed tomography to capture the feto-placental arterial geometry in 3D. A detailed description of rat fetal blood viscosity parameters was developed, and three different approaches to feto-placental haemodynamics were simulated in 3D using the finite volume method: Newtonian model, non-Newtonian Carreau-Yasuda model and Fåhræus-Lindqvist effect model. Significant variability in WSS was observed between different viscosity models. The physiologically-realistic simulations using the Fåhræus-Lindqvist effect and rat fetal blood estimates of viscosity revealed detailed patterns of WSS throughout the arterial network. We found WSS gradients at bifurcation regions, which may contribute to vessel enlargement, and sprouting and pruning during angiogenesis. This simulation of feto-placental haemodynamics shows the heterogeneous WSS distribution throughout the network and demonstrates the ability to determine physiologically-relevant WSS magnitudes, patterns and gradients. This model will help advance our understanding of vascular physiology and remodelling in the feto-placental network.
authors.affiliation: Vascular Engineering Laboratory, Harry Perkins Institute of Medical Research, Perth, Australia.|School of Mechanical and Chemical Engineering, The University of Western Australia, Perth, Australia.
authors.forename: Nikhilesh
authors.initials: N
authors.lastname: Bappoo
authors.affiliation: Vascular Engineering Laboratory, Harry Perkins Institute of Medical Research, Perth, Australia.|School of Mechanical and Chemical Engineering, The University of Western Australia, Perth, Australia.
authors.forename: Lachlan J
authors.initials: LJ
authors.lastname: Kelsey
authors.affiliation: Vascular Engineering Laboratory, Harry Perkins Institute of Medical Research, Perth, Australia.|School of Mechanical and Chemical Engineering, The University of Western Australia, Perth, Australia.
authors.forename: Louis
authors.initials: L
authors.lastname: Parker
authors.affiliation: School of Human Sciences, The University of Western Australia, Perth, Australia.
authors.forename: Tim
authors.initials: T
authors.lastname: Crough
authors.affiliation: Centre for Cardiovascular Science, University of Edinburgh, Edinburgh, UK.
authors.forename: Carmel M
authors.initials: CM
authors.lastname: Moran
authors.affiliation: Centre for Cardiovascular Science, University of Edinburgh, Edinburgh, UK.
authors.forename: Adrian
authors.initials: A
authors.lastname: Thomson
authors.affiliation: Centre for Cardiovascular Science, University of Edinburgh, Edinburgh, UK.
authors.forename: Megan C
authors.initials: MC
authors.lastname: Holmes
authors.affiliation: School of Human Sciences, The University of Western Australia, Perth, Australia.
authors.forename: Caitlin S
authors.initials: CS
authors.lastname: Wyrwoll
authors.affiliation: Vascular Engineering Laboratory, Harry Perkins Institute of Medical Research, Perth, Australia. barry.doyle@uwa.edu.au.|School of Mechanical and Chemical Engineering, The University of Western Australia, Perth, Australia. barry.doyle@uwa.edu.au.|Centre for Cardiovascular Science, University of Edinburgh, Edinburgh, UK. barry.doyle@uwa.edu.au.
authors.forename: Barry J
authors.initials: BJ
authors.lastname: Doyle
mesh_terms: D000818:Animals; D001158:Arteries / Q000502:physiology*; D001809:Blood Viscosity; D005260:Female; D005333:Fetus / Q000098:blood supply; D006439:Hemodynamics; D008955:Models, Cardiovascular; D010920:Placenta / Q000098:blood supply; D011247:Pregnancy; D051381:Rats; D013314:Stress, Mechanical; D055114:X-Ray Microtomography
keywords: Computational fluid dynamics; Feto-placental; Haemodynamics; Wall shear stress