Institute of Fluid Dynamics, ETH Zurich, Zurich, Switzerland.
Institute of Pharmacology and Toxicology, University of Zurich, Zurich, Switzerland.
PLoS Comput Biol. 2023 Oct 23;19(10):e1011496. doi: 10.1371/journal.pcbi.1011496. eCollection 2023 Oct.
Leptomeningeal collaterals (LMCs) connect the main cerebral arteries and provide alternative pathways for blood flow during ischaemic stroke. This is beneficial for reducing infarct size and reperfusion success after treatment. However, a better understanding of how LMCs affect blood flow distribution is indispensable to improve therapeutic strategies. Here, we present a novel in silico approach that incorporates case-specific in vivo data into a computational model to simulate blood flow in large semi-realistic microvascular networks from two different mouse strains, characterised by having many and almost no LMCs between middle and anterior cerebral artery (MCA, ACA) territories. This framework is unique because our simulations are directly aligned with in vivo data. Moreover, it allows us to analyse perfusion characteristics quantitatively across all vessel types and for networks with no, few and many LMCs. We show that the occlusion of the MCA directly caused a redistribution of blood that was characterised by increased flow in LMCs. Interestingly, the improved perfusion of MCA-sided microvessels after dilating LMCs came at the cost of a reduced blood supply in other brain areas. This effect was enhanced in regions close to the watershed line and when the number of LMCs was increased. Additional dilations of surface and penetrating arteries after stroke improved perfusion across the entire vasculature and partially recovered flow in the obstructed region, especially in networks with many LMCs, which further underlines the role of LMCs during stroke.
软脑膜侧支（LMCs）连接大脑主要动脉，在缺血性中风期间为血液流动提供替代途径。这有利于减少梗塞面积和治疗后的再灌注成功。然而，为了改善治疗策略，更好地了解 LMCs 如何影响血流分布是必不可少的。在这里，我们提出了一种新的计算方法，该方法将特定于病例的体内数据纳入计算模型，以模拟来自两种不同小鼠品系的大半真实微血管网络中的血液流动，这两种品系的特点是中脑动脉（MCA）和大脑前动脉（ACA）之间有许多和几乎没有 LMCs。该框架是独一无二的，因为我们的模拟与体内数据直接对齐。此外，它还允许我们对所有血管类型和具有无、少和多 LMCs 的网络进行定量分析灌注特征。我们表明，MCA 的闭塞直接导致血液重新分配，其特征是 LMCs 中的流量增加。有趣的是，在扩张 LMCs 后，MCA 侧微血管的灌注改善是以其他大脑区域的血液供应减少为代价的。这种效应在接近分水岭线的区域和当 LMCs 的数量增加时增强。中风后表面和穿透动脉的额外扩张改善了整个脉管系统的灌注，并部分恢复了阻塞区域的血流，尤其是在有许多 LMCs 的网络中，这进一步强调了 LMCs 在中风期间的作用。
