Kloosterman Astrid, Hierck Beerend, Westerweel Jerry, Poelma Christian
Laboratory for Aero & Hydrodynamics, Delft University of Technology, Delft, The Netherlands.
Department of Anatomy & Embryology, Leiden University Medical Center, Leiden, The Netherlands.
PLoS One. 2014 May 13;9(5):e96856. doi: 10.1371/journal.pone.0096856. eCollection 2014.
Since fluid dynamics plays a critical role in vascular remodeling, quantification of the hemodynamics is crucial to gain more insight into this complex process. Better understanding of vascular development can improve prediction of the process, and may eventually even be used to influence the vascular structure. In this study, a methodology to quantify hemodynamics and network structure of developing vascular networks is described. The hemodynamic parameters and topology are derived from detailed local blood flow velocities, obtained by in vivo micro-PIV measurements. The use of such detailed flow measurements is shown to be essential, as blood vessels with a similar diameter can have a large variation in flow rate. Measurements are performed in the yolk sacs of seven chicken embryos at two developmental stages between HH 13+ and 17+. A large range of flow velocities (1 µm/s to 1 mm/s) is measured in blood vessels with diameters in the range of 25-500 µm. The quality of the data sets is investigated by verifying the flow balances in the branching points. This shows that the quality of the data sets of the seven embryos is comparable for all stages observed, and the data is suitable for further analysis with known accuracy. When comparing two subsequently characterized networks of the same embryo, vascular remodeling is observed in all seven networks. However, the character of remodeling in the seven embryos differs and can be non-intuitive, which confirms the necessity of quantification. To illustrate the potential of the data, we present a preliminary quantitative study of key network topology parameters and we compare these with theoretical design rules.
由于流体动力学在血管重塑中起着关键作用，因此血流动力学的量化对于更深入了解这一复杂过程至关重要。更好地理解血管发育可以改善对该过程的预测，甚至最终可能用于影响血管结构。在本研究中，描述了一种量化发育中血管网络的血流动力学和网络结构的方法。血流动力学参数和拓扑结构是从详细的局部血流速度推导出来的，这些速度是通过体内微粒子图像测速技术（micro-PIV）测量获得的。结果表明，使用这种详细的血流测量至关重要，因为直径相似的血管流速可能有很大差异。在七个鸡胚的卵黄囊中，于HH 13+至17+的两个发育阶段进行测量。在直径为25 - 500 µm的血管中测量到了大范围的流速（1 µm/s至1 mm/s）。通过验证分支点处的流量平衡来研究数据集的质量。结果表明，七个胚胎的数据集质量在所有观察阶段都具有可比性，并且这些数据适合以已知的精度进行进一步分析。当比较同一胚胎的两个后续特征化网络时，在所有七个网络中都观察到了血管重塑。然而，七个胚胎中的重塑特征各不相同且可能不符合直觉，这证实了量化的必要性。为了说明这些数据的潜力，我们对关键网络拓扑参数进行了初步定量研究，并将其与理论设计规则进行比较。
