Disturbed flow in radial-cephalic arteriovenous fistulae for haemodialysis: low and oscillating shear stress locates the sites of stenosis
Disturbed flow in radial-cephalic arteriovenous fistulae for haemodialysis: low and oscillating shear stress locates the sites of stenosis
复制标题
DOI：
10.1093/ndt/gfr342
复制
发表时间：
2012-01-01
影响因子：
6.1
通讯作者：
Remuzzi, Andrea
中科院分区：
文献类型：
--
作者：
Ene-Iordache, Bogdan;Remuzzi, Andrea
背景。尽管最近的临床和技术进步，血管通路（VA）用于血液透析仍然有显著的早期失败率后，动静脉瘘（AVF）的创建。心室衰竭主要与触发血管壁疾病如内膜增生（IH）或动脉粥样硬化等现象的血流动力学条件有关。我们在理想的“端到端”和“端到端”放射头端吻合的三维模型中进行了瞬态计算流体动力学模拟，使用非牛顿血液和先前测量的流量和分割比作为边界条件。数值模拟允许充分表征AVF内的血流和血流动力学剪切应力模式，已知这是血管重构和疾病的主要决定因素。在动脉底和吻合旁静脉内壁发生血流停滞的区域，壁剪应力低且振荡。低剪应力区和振荡剪应力区位于先前关于AVF狭窄分布的实验研究中记录的腔径减少的相同部位。我们得出的结论是，即使暴露在高流速下，沿着AVF暴露于动脉粥样硬化易发剪应力的斑点区域也会通过触发IH而有利于血管狭窄。
Background. Despite recent clinical and technological advancements, the vascular access (VA) for haemodialysis still has significant early failure rates after arteriovenous fistula (AVF) creation. VA failure is mainly related to the haemodynamic conditions that trigger the phenomena of vascular wall disease such as intimal hyperplasia (IH) or atherosclerosis.Methods. We performed transient computational fluid dynamics simulations within idealized three-dimensional models of 'end-to-side' and 'end-to-end' radio-cephalic anastomosis, using non-Newtonian blood and previously measured flows and division ratio in subjects requiring primary access procedure as boundary conditions.Results. The numerical simulations allowed full characterization of blood flow inside the AVF and of patterns of haemodynamic shear stress, known to be the major determinant of vascular remodelling and disease. Wall shear stress was low and oscillating in zones where flow stagnation occurs on the artery floor and on the inner wall of the juxta-anastomotic vein.Conclusions. Zones of low and oscillatory shear stress were located in the same sites where luminal reduction was documented in previous experimental studies on sites stenosis distribution in AVF. We conclude that even when exposed to high flow rates, there are spot regions along the AVF exposed to athero-prone shear stress that favour vessel stenosis by triggering IH.