Compliance mismatch between an arteriovenous dialysis graft (AVG) and the connected vein is believed to result in disturbed haemodynamics around the graft–vein anastomosis and increased mechanical loading of the vein. Both phenomena are associated with neointimal hyperplasia development, which is the main reason for AVG patency loss. In this study, we use a patient-specific fluid structure interaction AVG model to assess whether AVG haemodynamics and mechanical loading can be optimised by using novel electrospun polyurethane (ePU) grafts, since their compliance can be better tuned to match that of the native veins, compared to gold standard, expanded polytetrafluoroethylene (ePTFE) grafts. It was observed that the magnitude of flow disturbances in the vein and the size of anastomotic areas exposed to highly oscillatory shear (\(\hbox {OSI} >0.25\)) and very high wall shear stress (\(>40 \hbox { Pa}\)) were largest for the ePTFE graft. Median strain and von Mises stress in the vein were similar for both graft types, whereas highest stress and strain were observed in the anastomosis of the ePU graft. Since haemodynamics were most favourable for the ePU graft simulation, AVG longevity might be improved by the use of ePU grafts.

中文翻译：

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电纺聚氨酯渗析接枝的血液动力学和力学性能的计算研究。

动静脉透析移植物（AVG）与连接的静脉之间的顺应性不匹配被认为会导致移植物静脉吻合周围的血液动力学受到干扰，并增加静脉的机械负荷。两种现象均与新内膜增生的发展有关，这是AVG开放性丧失的主要原因。在这项研究中，我们使用特定于患者的流体结构相互作用AVG模型来评估是否可以通过使用新型电纺聚氨酯（ePU）移植物来优化AVG的血流动力学和机械负荷，因为可以更好地调整其顺应性以匹配天然静脉的顺应性与金标准相比，膨胀聚四氟乙烯（ePTFE）接枝。观察到，在高振荡剪切作用下，静脉中流动干扰的大小和吻合区域的大小（\（\ hbox {OSI}> 0.25 \））和非常高的壁切应力（\（> 40 \ hbox {Pa} \））对于ePTFE接枝最大。两种移植物类型的静脉中位张力和von Mises应力相似，而在ePU移植物的吻合中观察到最高的应力和张力。由于血液动力学对ePU移植物模拟最有利，因此可以通过使用ePU移植物改善AVG寿命。