Steinman D A, Vinh B, Ethier C R, Ojha M, Cobbold R S, Johnston K W
Department of Mechanical Engineering, University of Toronto, Canada.
J Biomech Eng. 1993 Feb;115(1):112-8. doi: 10.1115/1.2895457.
In order to understand the possible role that hemodynamic factors may play in the pathogenesis of distal anastomotic intimal hyperplasia, we carried out numerical simulations of the flow field within a two-dimensional 45 degree rigid-walled end-to-side model anastomosis. The numerical code was tested and compared with experimental (photochromic dye tracer) studies using steady and near-sinusoidal waveforms, and agreement was generally very good. Using a normal human superficial femoral artery waveform, numerical simulations indicated elevated instantaneous wall shear stress magnitudes at the toe and heel of the graft-host junction and along the host artery bed. These sites also experienced highly variable wall shear stress behavior over the cardiac cycle, as well as elevated spatial gradients of wall shear stress. These observations provide additional evidence that intimal hyperplasia may be correlated to wall shear stresses over the cardiac cycle, high wall shear stress gradients, or a combination of the three. The limitations of the present work (especially in regard to the two-dimensional nature of the flow simulations) are discussed, and results are compared to previous observations about distal anastomotic intimal hyperplasia.
为了了解血流动力学因素在远端吻合口内膜增生发病机制中可能发挥的作用，我们对二维45度刚性壁端侧模型吻合口内的流场进行了数值模拟。该数值代码经过测试，并与使用稳定和近正弦波形的实验（光致变色染料示踪剂）研究进行了比较，总体吻合度非常好。使用正常人体股浅动脉波形进行数值模拟表明，在移植物-宿主交界处的趾部和跟部以及沿宿主动脉床处，瞬时壁面剪应力大小升高。这些部位在心动周期中还经历了高度可变的壁面剪应力行为，以及壁面剪应力的空间梯度升高。这些观察结果提供了额外的证据，表明内膜增生可能与心动周期中的壁面剪应力、高壁面剪应力梯度或三者的组合相关。讨论了本研究的局限性（特别是关于流动模拟的二维性质），并将结果与先前关于远端吻合口内膜增生的观察结果进行了比较。
