Charara J, Beaudoin G, Guidoin R
Biomaterials Institute, St-François d'Assise Hospital, Quebec, Canada.
Biomater Artif Cells Immobilization Biotechnol. 1992;20(1):1-21. doi: 10.3109/10731199209117854.
Although the main function of an arterial graft is to restore distal blood flow, there is evidence that certain local parameters of blood flow, particularly wall shear stresses, are important in determining the graft's long-term patency. Wall shear stresses were associated with intimal hyperplasia, intimal proliferation, and endothelial cell development, morphology, and attachment. Here we present a detailed method which permits the investigation of the wall shear stress acting on arteries and prostheses in dogs. The theory takes into account the nonlinear terms of the Navier-Stokes equations as well as the nonlinear behaviour and large deformation of the arterial wall. It is based on the numerical resolution of the nonlinear equations by the Crank-Nicolson method which was selected for its unconditional stability. Through the locally measured values of the pressure, pressure gradient, radius and flow rate, the velocity distribution and wall shear stress at a given location along the artery or the prosthesis, can be determined. Complete results on the same dog are presented for the distal aorta and for the middle of a chemically processed prosthesis, implanted as substitute in the thoracic aorta.
尽管动脉移植物的主要功能是恢复远端血流，但有证据表明，某些局部血流参数，尤其是壁面剪应力，对于确定移植物的长期通畅性很重要。壁面剪应力与内膜增生、内膜增殖以及内皮细胞的发育、形态和附着有关。在此，我们介绍一种详细方法，该方法可用于研究作用于犬类动脉和假体上的壁面剪应力。该理论考虑了纳维-斯托克斯方程的非线性项以及动脉壁的非线性行为和大变形。它基于通过克兰克-尼科尔森方法对非线性方程的数值求解，选择该方法是因其具有无条件稳定性。通过局部测量的压力、压力梯度、半径和流速值，可以确定沿动脉或假体给定位置处的速度分布和壁面剪应力。给出了同一只犬的远端主动脉以及植入胸主动脉作为替代物的化学处理假体中部的完整结果。
