Graduate School of Engineering Science, Osaka University, Osaka, Japan.
Graduate School of Integrated Sciences for Life, Hiroshima University, Hiroshima, Japan.
PLoS Comput Biol. 2023 Sep 8;19(9):e1011452. doi: 10.1371/journal.pcbi.1011452. eCollection 2023 Sep.
The cerebral arterial network covering the brain cortex has multiscale anastomosis structures with sparse intermediate anastomoses (O[102] μm in diameter) and dense pial networks (O[101] μm in diameter). Recent studies indicate that collateral blood supply by cerebral arterial anastomoses has an essential role in the prognosis of acute ischemic stroke caused by large vessel occlusion. However, the physiological importance of these multiscale morphological properties-and especially of intermediate anastomoses-is poorly understood because of innate structural complexities. In this study, a computational model of multiscale anastomoses in whole-brain-scale cerebral arterial networks was developed and used to evaluate collateral blood supply by anastomoses during middle cerebral artery occlusion. Morphologically validated cerebral arterial networks were constructed by combining medical imaging data and mathematical modeling. Sparse intermediate anastomoses were assigned between adjacent main arterial branches; the pial arterial network was modeled as a dense network structure. Blood flow distributions in the arterial network during middle cerebral artery occlusion simulations were computed. Collateral blood supply by intermediate anastomoses increased sharply with increasing numbers of anastomoses and provided one-order-higher flow recoveries to the occluded region (15%-30%) compared with simulations using a pial network only, even with a small number of intermediate anastomoses (≤10). These findings demonstrate the importance of sparse intermediate anastomoses, which are generally considered redundant structures in cerebral infarction, and provide insights into the physiological significance of the multiscale properties of arterial anastomoses.
大脑皮层的脑动脉网络具有多尺度吻合结构，具有稀疏的中间吻合（直径为 O[102]μm）和密集的软脑膜网络（直径为 O[101]μm）。最近的研究表明，脑动脉吻合的侧支血液供应在大血管闭塞引起的急性缺血性中风的预后中起着重要作用。然而，由于固有结构的复杂性，这些多尺度形态特性，特别是中间吻合的生理重要性，仍知之甚少。在这项研究中，开发了一种全脑尺度脑动脉网络多尺度吻合的计算模型，并用于评估大脑中动脉闭塞期间吻合的侧支血液供应。通过结合医学成像数据和数学建模，构建了形态学验证的脑动脉网络。在相邻的主要动脉分支之间分配稀疏的中间吻合；将软脑膜动脉网络建模为密集的网络结构。在大脑中动脉闭塞模拟期间计算了动脉网络中的血流分布。与仅使用软脑膜网络的模拟相比，中间吻合的侧支血液供应随着吻合数量的增加而急剧增加，为闭塞区域提供了更高一级的血流恢复（15%-30%），即使吻合数量较少（≤10）也是如此。这些发现表明稀疏中间吻合的重要性，这些吻合通常被认为是脑梗死中的冗余结构，并为动脉吻合的多尺度特性的生理意义提供了深入了解。
