DIMeG, Politecnico di Bari, via Re David 200, 70125 Bari, Italy.
J Biomech. 2011 Jun 3;44(9):1684-90. doi: 10.1016/j.jbiomech.2011.03.036. Epub 2011 Apr 14.
Two different aortic prostheses can be used for performing the Bentall procedure: a standard straight graft and the Valsalva graft that better reproduces the aortic root anatomy. The aim of the present work is to study the effect of the graft geometry on the blood flow when a bileaflet mechanical heart valve is used, as well as to evaluate the stress concentration near the suture line where the coronary arteries are connected to graft. An accurate three-dimensional numerical method is proposed, based on the immersed boundary technique. The method accounts for the interactions between the flow and the motion of the rigid leaflets and of the deformable aortic root, under physiological pulsatile conditions. The results show that the graft geometry only slightly influences the leaflets dynamics, while using the Valsalva graft the stress level near the coronary-root anastomoses is about half that obtained using the standard straight graft.
两种不同的主动脉假体可用于进行 Bentall 手术：标准直移植物和更能再现主动脉根部解剖结构的 Valsalva 移植物。本工作旨在研究在使用双叶机械心脏瓣膜时，移植物几何形状对血流的影响，以及评估冠状动脉与移植物连接的缝线附近的应力集中情况。提出了一种基于浸入边界技术的精确三维数值方法。该方法考虑了在生理脉动条件下，流场与刚性瓣叶以及可变形主动脉根部的运动之间的相互作用。结果表明，移植物几何形状仅略微影响瓣叶动力学，而使用 Valsalva 移植物时，冠状动脉-根部吻合处的应力水平约为使用标准直移植物时的一半。
