Dept. of Mechanical Engineering, McGill University, Macdonald Engineering Building, 817 Sherbrooke St. W, Montreal H3A 0C3, Quebec, Canada.
Department of Aerospace and Mechanical Engineering, University of Arizona, 1130 N. Mountain Ave., Tucson AZ 85721, USA.
J Biomech. 2019 Mar 27;86:132-140. doi: 10.1016/j.jbiomech.2019.01.053. Epub 2019 Feb 12.
Woven Dacron grafts are currently used for the surgical treatment of aortic aneurysm and acute dissection, two otherwise fatal pathologies when aortic wall rupture occurs. While Dacron is chosen for aortic grafts because of characteristics such as biocompatibility and durability, few data are available about the dynamic response of Dacron prosthetic devices and about their side effects on the cardiovascular system. In this study, a Dacron graft was subjected to physiological flow conditions in a specifically-developed mock circulatory loop. Experiments were conducted at different physiological pulsation-per-minute rates. Results show that, in comparison to an aortic segment of the same length, the prosthesis is extremely stiffer circumferentially, thus limiting the dynamical radial expansion responsible for the Windkessel effect in human arteries. The prosthesis is instead excessively compliant in the axial direction and develops preferentially bending oscillations. This very different dynamic behaviour with respect to the human aorta can alter cardiovascular pressure and flow dynamics resulting in long-term implant complications.
目前，编织涤纶移植物用于治疗主动脉瘤和急性夹层这两种疾病，当主动脉壁破裂时，这两种疾病通常是致命的。尽管涤纶因其生物相容性和耐用性等特点而被选为主动脉移植物，但关于涤纶假体的动态响应及其对心血管系统的副作用的数据却很少。在这项研究中，涤纶移植物在专门开发的模拟循环回路中受到生理流动条件的影响。实验在不同的生理脉动每分钟速率下进行。结果表明，与相同长度的主动脉节段相比，假体在圆周方向上极其僵硬，从而限制了负责人类动脉脉压效应的动态径向扩张。相反，假体在轴向方向上过度顺应，并优先产生弯曲振动。与人体主动脉相比，这种非常不同的动态行为会改变心血管压力和流动动力学，导致长期植入物并发症。
