论文标题

关于颅内动脉瘤壁的曲率在确定其机械反应,局部血液动力学和破裂的可能性方面发挥的主要作用

On the major role played by the curvature of intracranial aneurysms walls in determining their mechanical response, local hemodynamics, and rupture likelihood

论文作者

Oliveira, Iago, Cardiff, Philip, Baccin, Carlos Eduardo, Tatit, Rafael, Gasche, José Luiz

论文摘要

已知颅内动脉瘤(IAS)壁的特性是由与IA SAC相邻的基础血液动力学驱动的。存在不同的途径,解释了血液动力学与局部组织特性之间的联系。如果人们希望计算患者特异性IA壁的机械反应并预测其破裂,那么这种理论的出现至关重要。除了血液动力学和组织特性外,还可以假设机械响应还取决于局部形态,更具体地说,是壁弯曲的,在高度弯曲的壁部分时值较大。尽管如此,这与对IA破裂位点的观察相矛盾,更经常在圆顶上发现,那里的曲率较低。这似乎矛盾表明局部血液动力学,壁上形态和机械反应之间存在复杂的相互作用,这需要进一步研究。这是这项工作的主要目标。我们通过分析壁的不同区域的应力和拉伸场来实现这一目标,以作为IAS样本,这些样本已根据特定的局部血液动力学和局部曲率进行了分类。使用OpenFOAM(Solids4FOAM工具箱)实现的单向流体 - 固定相互作用策略进行了脉冲数值模拟。我们发现,可变最佳与高应力和拉伸区域相关的是壁曲率。此外,我们的数据表明,局部曲率和局部血液动力学之间存在联系,表明曲率是一种可用于评估机械反应和血液动力学条件的特性,此外,还建议基于曲率预测破裂可能性的新指标。

The properties of intracranial aneurysms (IAs) walls are known to be driven by the underlying hemodynamics adjacent to the IA sac. Different pathways exist explaining the connections between hemodynamics and local tissue properties. The emergence of such theories is essential if one wishes to compute the mechanical response of a patient-specific IA wall and predict its rupture. Apart from the hemodynamics and tissue properties, one could assume that the mechanical response also depends on the local morphology, more specifically, the wall curvature, with larger values at highly-curved wall portions. Nonetheless, this contradicts observations of IA rupture sites more often found at the dome, where the curvature is lower. This seeming contradiction indicates a complex interaction between local hemodynamics, wall morphology, and mechanical response, which warrants further investigation. This was the main goal of this work. We accomplished this by analysing the stress and stretch fields in different regions of the wall for a sample of IAs, which have been classified based on particular local hemodynamics and local curvature. Pulsatile numerical simulations were performed using the one-way fluid-solid interaction strategy implemented in OpenFOAM (solids4foam toolbox). We found that the variable best correlated with regions of high stress and stretch was the wall curvature. Additionally, our data suggest a connection between the local curvature and local hemodynamics, indicating that the curvature is a property that could be used to assess both mechanical response and hemodynamic conditions, and, moreover, to suggest new metrics based on the curvature to predict the likelihood of rupture.

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