Vascular Engineering Laboratory, Harry Perkins Institute of Medical Research, QEII Medical Centre and the UWA Centre for Medical Research, The University of Western Australia, Nedlands, WA, 6009, Australia.
School of Engineering, The University of Western Australia, Perth, WA, 6009, Australia.
Ann Biomed Eng. 2021 Sep;49(9):2183-2195. doi: 10.1007/s10439-021-02749-4. Epub 2021 Mar 1.
The placenta uniquely develops to orchestrate maternal adaptations and support fetal growth and development. The expansion of the feto-placental vascular network, in part, underpins function. However it is unclear how vascular development is synergistically influenced by hemodynamics and how impairment may lead to fetal growth restriction (FGR). Here, we present a robust framework consisting of ex vivo placental casting, imaging and computational fluid dynamics of rat feto-placental networks where we investigate inlet (steady and transient) and outlet (zero-pressure, Murray's Law, asymmetric fractal trees and porous blocks) boundary conditions in a model of growth-restriction. We show that the Murray's Law flow-split boundary condition is not always appropriate and that mean steady-state inlet conditions produce comparable results to transient flow. However, we conclude that transient simulations should be adopted as they provide a larger amount of valuable data, a necessity to bridge the current knowledge gap in placental biomechanics. We also show preliminary data on changes in flow, shear stress, and flow deceleration between control and growth-restricted feto-placental networks. Our proposed framework provides a standardized approach for structural and hemodynamic analysis of feto-placental vasculature and has the potential to enhance our understanding of placental function.
胎盘独特地发育，以协调母体适应和支持胎儿的生长和发育。胎儿胎盘血管网络的扩张部分支撑了这一功能。然而，血流动力学如何协同影响血管发育以及损伤如何导致胎儿生长受限（FGR）尚不清楚。在这里，我们提出了一个稳健的框架，包括大鼠胎儿胎盘网络的体外胎盘铸型、成像和计算流体动力学，我们在生长受限模型中研究了入口（稳态和瞬态）和出口（零压力、默里定律、非对称分形树和多孔块）边界条件。我们表明，默里定律的流量分配边界条件并不总是合适的，稳态入口条件产生的结果与瞬态流相似。然而，我们得出结论，应该采用瞬态模拟，因为它们提供了更多有价值的数据，这是弥合胎盘生物力学当前知识差距的必要条件。我们还展示了在对照和生长受限的胎儿胎盘网络之间的流量、剪切应力和流量减速变化的初步数据。我们提出的框架为胎儿胎盘血管的结构和血液动力学分析提供了一种标准化的方法，有可能增强我们对胎盘功能的理解。
