Zhang Qi, Gao Bin, Chang Yu
School of Life Sciences and BioEngineering, Beijing University of Technology, Beijing, China (mainland).
School of Life Science and BioEngineering, Beijing University of Technology, Beijing, China (mainland).
Med Sci Monit. 2017 Feb 27;23:1043-1054. doi: 10.12659/msm.900481.
BACKGROUND Partial support, as a novel support mode, has been widely applied in clinical practice and widely studied. However, the precise mechanism of partial support of LVAD in the intra-ventricular flow pattern is unclear. MATERIAL AND METHODS In this study, a patient-specific left ventricular geometric model was reconstructed based on CT data. The intra-ventricular flow pattern under 3 simulated conditions - "heart failure", "partial support", and "full support" - were simulated by using fluid-structure interaction (FSI). The blood flow pattern, wall shear stress (WSS), time-average wall shear stress (TAWSS), oscillatory shear index (OSI), and relative residence time (RRT) were calculated to evaluate the hemodynamic effects. RESULTS The results demonstrate that the intra-ventricular flow pattern is significantly changed by the support level of BJUT-II VAD. The intra-ventricular vortex was enhanced under partial support and was eliminated under full support, and the high OSI and RRT regions changed from the septum wall to the cardiac apex. CONCLUSIONS In brief, the support level of the BJUT-II VAD has significant effects on the intra-ventricular flow pattern. The partial support mode of BJUT-II VAD can enhance the intra-ventricular vortex, while the distribution of high OSI and RRT moved from the septum wall to the cardiac apex. Hence, the partial support mode of BJUT-II VAD can provide more benefit for intra-ventricular flow pattern.
背景 作为一种新型的支持模式，部分支持已在临床实践中广泛应用并得到广泛研究。然而，左心室辅助装置（LVAD）在心室内部血流模式中的部分支持的确切机制尚不清楚。材料与方法 在本研究中，基于CT数据重建了患者特异性的左心室几何模型。使用流固耦合（FSI）模拟了“心力衰竭”、“部分支持”和“完全支持”3种模拟条件下的心室内血流模式。计算血流模式、壁面剪应力（WSS）、时间平均壁面剪应力（TAWSS）、振荡剪切指数（OSI）和相对停留时间（RRT）以评估血流动力学效应。结果 结果表明，BJUT-II型心室辅助装置的支持水平显著改变了心室内血流模式。部分支持下心室内涡流增强，完全支持下涡流消除，高OSI和RRT区域从室间隔壁转移至心尖。结论 简而言之，BJUT-II型心室辅助装置的支持水平对心室内血流模式有显著影响。BJUT-II型心室辅助装置的部分支持模式可增强心室内涡流，同时高OSI和RRT的分布从室间隔壁转移至心尖。因此，BJUT-II型心室辅助装置的部分支持模式可为心室内血流模式带来更多益处。
