Arterio-Venous Fistulae (AVF) are regarded as the “gold standard” method of vascular access for patients with end-stage renal disease who require haemodialysis. However, a large proportion of AVF do not mature, and hence fail, as a result of various pathologies such as Intimal Hyperplasia (IH). Unphysiological flow patterns, including high-frequency flow unsteadiness, associated with the unnatural and often complex geometries of AVF are believed to be implicated in the development of IH. In the present study, we employ a Mesh Adaptive Direct Search optimisation framework, computational fluid dynamics simulations, and a new cost function to design a novel non-planar AVF configuration that can suppress high-frequency unsteady flow. A prototype device for holding an AVF in the optimal configuration is then fabricated, and proof-of-concept is demonstrated in a porcine model. Results constitute the first use of numerical optimisation to design a device for suppressing potentially pathological high-frequency fl...

中文翻译：

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抑制动静脉瘘中的不稳定血流

动静脉瘘（AVF）被认为是需要血液透析的终末期肾病患者血管通路的“金标准”方法。然而，由于内膜增生 (IH) 等各种病理原因，很大一部分 AVF 未成熟，因此失败。与 AVF 不自然且通常复杂的几何形状相关的非生理流动模式，包括高频流动不稳定，被认为与 IH 的发展有关。在本研究中，我们采用网格自适应直接搜索优化框架、计算流体动力学模拟和新的成本函数来设计一种可以抑制高频不稳定流的新型非平面 AVF 配置。然后制造用于将 AVF 保持在最佳配置的原型设备，并在猪模型中证明了概念验证。结果构成了第一次使用数值优化来设计一种抑制潜在病理性高频信号的装置。