Department of Mechanical and Materials Engineering, Wright State University, Dayton, OH, 45435, USA.
Department of Mechanical and Materials Engineering, Wright State University, Dayton, OH, 45435, USA.
Comput Biol Med. 2023 Sep;163:107198. doi: 10.1016/j.compbiomed.2023.107198. Epub 2023 Jun 20.
Hemodynamic mechanisms of the formation and growth of intracranial aneurysms (IA) in monozygotic twins (MTs) are still under-reported. To partially fill such knowledge gap, this study employed an experimentally validated numerical model to compare hemodynamics in 3 anatomical and 5 ablation study neurovascular models from a rare pair of MTs in terms of 7 critical hemodynamic parameters. Numerical results showed significant differences in hemodynamics between the MTs, although they share the same genes, indicating that genetic mutation and environmental factors might affect neurovascular morphologies and cause hemodynamic changes. After virtual removals of IAs in the ablation study, the locations where the aneurysmal sac/bleb generated in bifurcated anterior cerebral arteries (ACAs) register a locally high instantaneous wall shear stress (IWSS) of 52.9 and 70.1 Pa at the systolic peak in twin A and twin B, respectively. Same scenario can be observed in the distribution of instantaneous wall shear stress gradient (IWSSG), with 571.1 Pa/mm for twin A and 301.3 Pa/mm for twin B due to aggressive blood impingements, leading to IA generation. The fenestrated complex approaching ACA bifurcations in twin A may assist IA growth and rupture, via. Causing abnormal IWSS of 116.3 Pa, IWSSG of 832.5 Pa/mm, and oscillatory shear index (OSI) of 0.49. The bleb in twin B has high risks of progression and possible rupture as the IA suffers relatively low IWSS and high OSI. Additionally, IA generation can change blood flow rates in each connected artery, then affecting blood supplies to associated tissues and organs.
在同卵双胞胎（MTs）中，颅内动脉瘤（IA）形成和生长的血流动力学机制仍报道较少。为了部分填补这一知识空白，本研究使用经过实验验证的数值模型，根据 7 个关键血流动力学参数，比较了一对罕见 MT 中 3 个解剖学和 5 个消融研究神经血管模型的血流动力学。数值结果表明，尽管 MTs 具有相同的基因，但它们的血流动力学存在显著差异，这表明基因突变和环境因素可能影响神经血管形态并导致血流动力学变化。在消融研究中虚拟去除 IA 后，在分叉大脑前动脉（ACA）中动脉瘤囊/泡产生的位置，在 twin A 和 twin B 的收缩峰值处分别记录到局部高瞬时壁切应力（IWSS）为 52.9 和 70.1 Pa。在瞬时壁切应力梯度（IWSSG）的分布中也可以观察到相同的情况，由于血液的强烈冲击，twin A 的 IWSSG 为 571.1 Pa/mm，twin B 的 IWSSG 为 301.3 Pa/mm，导致 IA 的产生。twin A 中接近 ACA 分叉的有孔复合体可能通过引起异常的 IWSS 为 116.3 Pa、IWSSG 为 832.5 Pa/mm 和振荡剪切指数（OSI）为 0.49 来促进 IA 的生长和破裂。由于 IA 受到相对较低的 IWSS 和较高的 OSI，twin B 中的动脉瘤泡具有进展和可能破裂的高风险。此外，IA 的产生会改变每个相连动脉中的血流速度，从而影响相关组织和器官的血液供应。
