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 (CFD) 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 (μCT) to capture rat 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 Fåhraeus-Lindqvist effect model. Significant variability in WSS was observed between different viscosity models. The physiologically-realistic simulations using the Fåhraeus-Lindqvist effect and rat fetal blood estimates of viscosity revealed detailed patterns of WSS throughout the arterial network, with WSS gradients observed at bifurcation regions, which may contribute to vessel 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.
In REF a 3D reconstruction of arterial network from micro-computed tomography is obtained for the study of fluid dynamics of the placenta (experimentally, from a rat).
Viscosity and haemodynamics in a late gestation rat feto-placental arterial network.
Biomechanics and modeling in mechanobiology
Biomechanics and modeling in mechanobiology
Biology Medicine