LaBS, Chemistry, Material and Chemical Engineering Department "Giulio Natta", Politecnico di Milano, Italy.
LaBS, Chemistry, Material and Chemical Engineering Department "Giulio Natta", Politecnico di Milano, Italy.
Microvasc Res. 2019 Mar;122:101-110. doi: 10.1016/j.mvr.2018.11.003. Epub 2018 Nov 16.
Fluid homeostasis is required for life. Processes involved in fluid balance are strongly related to exchanges at the microvascular level. Computational models have been presented in the literature to analyze the microvascular-interstitial interactions. As far as we know, none of those models consider a physiological description for the lymphatic drainage-interstitial pressure relation. We develop a computational model that consists of a network of straight cylindrical vessels and an isotropic porous media with a uniformly distributed sink term acting as the lymphatic system. In order to describe the lymphatic flow rate, a non-linear function of the interstitial pressure is defined, based on literature data on the lymphatic system. The proposed model of lymphatic drainage is compared to a linear one, as is typically used in computational models. To evaluate the response of the model, the two are compared with reference to both physiological and pathological conditions. Differences in the local fluid dynamic description have been observed using the non-linear model. In particular, the distribution of interstitial pressure is heterogeneous in all the cases analyzed. The resulting averaged values of the interstitial pressure are also different, and they agree with literature data when using the non-linear model. This work highlights the key role of lymphatic drainage and its modeling when studying the fluid balance in microcirculation for both to physiological and pathological conditions, e.g. uremia.
流体平衡对于生命至关重要。涉及流体平衡的过程与微血管水平的交换密切相关。文献中已经提出了计算模型来分析微血管-间质相互作用。据我们所知，这些模型都没有考虑到淋巴引流-间质压力关系的生理描述。我们开发了一个计算模型，由一个直圆柱形血管网络和各向同性多孔介质组成，其中一个均匀分布的汇项作为淋巴系统。为了描述淋巴流速，根据淋巴系统的文献数据，定义了一个与间质压力的非线性函数。所提出的淋巴引流模型与通常在计算模型中使用的线性模型进行了比较。为了评估模型的响应，将这两种模型与生理和病理条件进行了比较。使用非线性模型观察到局部流体动力学描述的差异。特别是，在分析的所有情况下，间质压力的分布都是不均匀的。使用非线性模型时，得到的间质压力平均值也不同，并且与文献数据一致。这项工作强调了在研究微循环中的流体平衡时，淋巴引流及其建模的关键作用，例如在尿毒症等生理和病理条件下。
