Assessment of Hemodynamic Conditions in the Aorta Following Root Replacement with Composite Valve-Conduit Graft
Assessment of Hemodynamic Conditions in the Aorta Following Root Replacement with Composite Valve-Conduit Graft
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DOI：
10.1007/s10439-015-1453-x
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发表时间：
2016-05-01
影响因子：
3.8
通讯作者：
Xu, Xiao Yun
中科院分区：
文献类型：
--
作者：
Cheng, Zhuo;Kidher, Emaddin;Xu, Xiao Yun
本文介绍了四名患者在用复合生物瓣膜-管道置换后的动脉中的详细血流动力学分析。为每例患者建立基于磁共振图像的计算模型，边界条件包括主动脉根部的受试者特定三维流入速度曲线和模型出口处的中心压力波形。还包括两名正常受试者进行比较。本研究的目的是研究瓣膜管道对近端和远端主动脉中流量的影响。结果表明，植入复合瓣膜-管道后，主动脉内的旋涡流结构和血流动力学参数发生了改变，螺旋流指数略有降低，壁面切应力增加，壁面剪切不均匀性增加。个体间分析显示，根据升主动脉中的管道配置，患者之间存在不同的血流动力学状况，这是确定术后主动脉血流的关键因素。在管道中引入自然曲率以在管道和天然主动脉之间产生平滑过渡可以帮助防止主动脉弓中发生逆行和再循环流动，这在需要替换大部分或整个升主动脉时特别重要。
This paper presents the analysis of detailed hemodynamics in the aortas of four patients following replacement with a composite bio-prosthetic valve-conduit. Magnetic resonance image-based computational models were set up for each patient with boundary conditions comprising subject-specific three-dimensional inflow velocity profiles at the aortic root and central pressure waveform at the model outlet. Two normal subjects were also included for comparison. The purpose of the study was to investigate the effects of the valve-conduit on flow in the proximal and distal aorta. The results suggested that following the composite valve-conduit implantation, the vortical flow structure and hemodynamic parameters in the aorta were altered, with slightly reduced helical flow index, elevated wall shear stress and higher non-uniformity in wall shear compared to normal aortas. Inter-individual analysis revealed different hemodynamic conditions among the patients depending on the conduit configuration in the ascending aorta, which is a key factor in determining post-operative aortic flow. Introducing a natural curvature in the conduit to create a smooth transition between the conduit and native aorta may help prevent the occurrence of retrograde and recirculating flow in the aortic arch, which is particularly important when a large portion or the entire ascending aorta needs to be replaced.