Abstract：
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.
摘要：
单卵双胞胎（MT）中颅内动脉瘤（IA）形成和生长的血流动力学机制仍未得到充分报道。为了部分填补这样的知识空白，这项研究采用了一个经过实验验证的数值模型,根据7个关键的血流动力学参数,比较了3个解剖模型和5个消融研究神经血管模型的血流动力学.数值结果表明，MTs之间的血流动力学存在显着差异，虽然它们有相同的基因,表明基因突变和环境因素可能影响神经血管形态并引起血流动力学变化。在消融研究中虚拟去除IAs后，在双胎A和双胎B中，在分叉的大脑前动脉（ACA）中产生的动脉瘤囊/泡的位置在收缩期峰值处记录了52.9和70.1Pa的局部高瞬时壁剪切应力（IWSS）。分别。在瞬时壁面剪应力梯度（IWSSG）的分布中可以观察到相同的情况，由于积极的血液冲击，双胞胎A为571.1Pa/mm，双胞胎B为301.3Pa/mm，导致IA一代。双胞胎A中接近ACA分叉的开窗复合体可能有助于IA生长和破裂，via.导致116.3Pa的异常IWSS，832.5Pa/mm的IWSSG，振荡剪切指数(OSI)为0.49。由于IA遭受相对较低的IWSS和较高的OSI，因此双胞胎B中的气泡具有很高的进展和可能的破裂风险。此外,IA代可以改变每个相连动脉的血流速度，然后影响相关组织和器官的血液供应。
