Chandran K B, Gao D, Han G, Baraniewski H, Corson J D
Department of Biomedical Engineering, University of Iowa, Iowa City 52245.
Med Biol Eng Comput. 1992 Jul;30(4):413-8. doi: 10.1007/BF02446179.
A finite-element simulation of an end-to-end artery/graft anastomosis has been presented in this study to evaluate the distribution of compliance and stresses in the vicinity of the anastomosis due to any mismatch in compliance characteristics. The arterial wall was assumed to be made of linear isotropic elastic material in this simplified model and a static analysis was performed with a mean arterial pressure loading of the artery-graft model. Anastomoses to vein grafts and both Dacron and polytetrafluoroethylene (PTFE) grafts were studied. The results suggested the presence of a hypercompliant zone on the arterial side and a region of high tensile stresses in the wall on the graft side of the anastomosis. The presence of a hypercompliant zone has been reported from previous in vivo studies. The hypercompliance was larger with Dacron and PTFE grafts compared with that with the vein graft. However, larger tensile stresses were present in the wall of the vein graft compared with the synthetic grafts. The analysis further showed that increasing the diameter of the graft compared with the host artery to increase flow through the implant will result in a significant increase in the hypercompliance on the arterial side. Such simulation studies may prove valuable in studying the effects of compliance mismatch and suggest ways to improve the design of small diameter vascular grafts.
本研究提出了一种端到端动脉/移植物吻合术的有限元模拟，以评估由于顺应性特征不匹配而在吻合口附近产生的顺应性和应力分布。在这个简化模型中，动脉壁被假定为由线性各向同性弹性材料制成，并对动脉-移植物模型施加平均动脉压载荷进行静态分析。研究了与静脉移植物以及涤纶和聚四氟乙烯（PTFE）移植物的吻合情况。结果表明，在吻合口的动脉侧存在一个高顺应性区域，在移植物侧的壁上存在一个高拉伸应力区域。先前的体内研究已经报道了高顺应性区域的存在。与静脉移植物相比，涤纶和PTFE移植物的高顺应性更大。然而，与合成移植物相比，静脉移植物壁上存在更大的拉伸应力。分析进一步表明，与宿主动脉相比增加移植物直径以增加通过植入物的血流量，将导致动脉侧的高顺应性显著增加。此类模拟研究在研究顺应性不匹配的影响以及提出改进小直径血管移植物设计的方法方面可能具有重要价值。
