Computational investigations of a new prosthetic femoral-popliteal bypass graft design
Computational investigations of a new prosthetic femoral-popliteal bypass graft design
复制标题
DOI：
10.1016/j.jvs.2005.08.016
复制
发表时间：
2005-12-01
影响因子：
4.3
通讯作者：
McGloughlin, T
中科院分区：
文献类型：
--
作者：
O'Brien, TP;Grace, P;McGloughlin, T
目的：假体股腘动脉旁路术是通过端侧吻合术进行的，疾病可能在远端发展;这可能导致长期通畅率不佳。扰动流特性被假设为促进疾病发展的主要因素。本研究的目的是提出一种新的假体股腘动脉旁路移植物的配置，专门设计，以减少或消除某些疾病的影响因素，对宿主动脉的作用。申报器械包含朝向其远端的流线型分叉，导致两个端对端吻合，而不是传统手术中的单端对侧吻合。比较理想化的代表性，它和传统的端侧吻合特定的股动脉流速。比较了速度矢量图和壁面剪应力等值线图形式的定性结果，定量结果检查了壁面剪应力的大小和梯度沿每个移植物模型的床和顶的沿着。通过每个连接处的速度矢量图表明，所提出的移植物配置促进流线型流动，并有助于减少与传统端侧吻合相关的流动再循环和分离区域的幅度。在峰值速度下，趾远端的流动分离区域被消除，如趾壁剪切应力从传统吻合术中的-0.2 Pa变化到申报器械中的+0.5 Pa所证明的。正常的完全发展的血流在远端宿主动脉中更快地发生，在距脚趾下游约15 mm处，而不像常规情况下的20 mm。所提出的设计结果在股动脉脉搏的减速阶段在脚趾下方的动脉床附近的峰值壁剪切应力和峰值壁剪切应力梯度的减少高达58%和86%。对申报器械进行的体外试验表明，通过连接处的血流的流线型性质确实导致宿主动脉连接处内的血流动力学状况受到较少干扰。异常的壁面剪应力大小和梯度降低，并且在远端宿主动脉中更快地出现正常的充分发展的血流。这表明，申报的移植物可能具有与研究增加假体股腘动脉旁路移植物通畅率相关的设计属性。所提出的装置的一个缺点是假体本身内存在显着的流动再循环和分离。
Objective: Prosthetic femoral-popliteal bypasses are performed by using an end-to-side anastomosis, and disease can develop at the distal end; this can lead to poor long-term patency rates. Disturbed flow characteristics are hypothesized as being a major factor in promoting disease development. The objective of this study was to propose a new prosthetic femoral-popliteal bypass graft configuration specifically engineered to reduce or eliminate certain disease-influencing factors that act on the host artery.Methods. The proposed device contains a streamlined bifurcation toward its distal end that results in two end-to-end anastomoses, rather than the single end-to-side anastomosis in the traditional procedure. Comparisons are made between idealized representations of it and the traditional end-to-side anastomosis for specific femoral artery flow rates. Qualitative results in the form of velocity vector plots and wall shear stress contour plots are compared, and quantitative results examine the wall shear stress magnitudes and gradients along the bed and roof of each graft model.Results. Velocity vector plots through each junction suggest that the proposed graft configuration promotes streamlined flow and helps to reduce the magnitude of flow recirculation and separation regions associated with the traditional end-to-side anastomosis. At peak velocity, the flow separation region distal to the toe is eliminated, as evidenced by the change in toe wall shear stress from -0.2 Pa in the traditional anastomosis to +0.5 Pa in the proposed device. Normal fully developed flow occurs sooner in the distal host artery, approximately 15 nun downstream from the toe, unlike 20 nun in the conventional case. The proposed design results in reductions of up to 58% in peak wall shear stress and 86% in peak wall shear stress gradient during the decelerative phase of the femoral pulse in the vicinity of the artery bed below the toe.Conclusions. In vitro tests on the proposed device suggest that the streamlined nature of blood flow through the junction does result in less disturbed hemodynamic conditions within the host artery junction. Abnormal wall shear stress magnitudes and gradients are reduced, and normal fully developed flow occurs sooner in the distal host artery. This suggests that the proposed graft may have design attributes that are relevant in the search for increased prosthetic femoral-popliteal bypass graft patency rates. A drawback of the proposed device is that significant flow recirculation and separation exist within the prosthesis itself.