School of Life Science and Bioengineering, Beijing University of Technology, Beijing 100124, PR China.
School of Life Science and Bioengineering, Beijing University of Technology, Beijing 100124, PR China.
Comput Methods Programs Biomed. 2020 Dec;197:105763. doi: 10.1016/j.cmpb.2020.105763. Epub 2020 Sep 16.
BACKGROUND AND OBJECTIVE: The series type of LVAD (i.e., BJUT-II VAD) is a novel left ventricular assist device, whose effects on the aortic valve remain unclear. METHODS: The biomechanical effects of BJUT-II VAD on the aortic valve were investigated by using a fluid-structure interaction method. The geometric model of BJUT-II VAD was virtually implanted into the ascending aorta to generate the realistic flow pattern for the aortic valve (i.e., support). In addition, the biomechanical states of the aortic valve without BJUT-II VAD support was computed as control (i.e., control case). RESULTS: Results demonstrated that the biomechanical effects of BJUT-II VAD were quite different from that resulting from traditional "bypass LVAD." Compared with those in the control case, BJUT-II VAD support could significantly reduce the stress load of the leaflet (maximum stress, 0.5 MPa in the control case vs. 0.12 MPa in the support case). Similarly, the rapid valve opening time (100 ms in the control case vs. 175 ms in the support case) and rapid valve closing time (50 ms in the control case vs. 150 ms in the support case) in the support case were obviously longer than those in the control case. Moreover, BJUT-II VAD support reduced retrograde blood flow during the diastolic phase and significantly changed the distribution of WSS of the leaflets. CONCLUSIONS: In summary, while unloading the left ventricle, BJUT-II VAD could provide beneficial biomechanical states for the aortic leaflets, thereby reducing the risk of aortic valve disease.
背景与目的:串联式 LVAD(即 BJUT-II VAD)是一种新型左心室辅助装置,其对主动脉瓣的影响尚不清楚。
方法:采用流固耦合方法研究 BJUT-II VAD 对主动脉瓣的生物力学影响。将 BJUT-II VAD 的几何模型虚拟植入升主动脉,以产生主动脉瓣的真实血流模式(即支持)。此外,还计算了没有 BJUT-II VAD 支持时主动脉瓣的生物力学状态作为对照(即对照病例)。
结果:结果表明,BJUT-II VAD 的生物力学效应与传统的“旁路 LVAD”有很大的不同。与对照病例相比,BJUT-II VAD 支持可显著降低瓣叶的应力负荷(对照病例最大应力为 0.5 MPa,支持病例为 0.12 MPa)。同样,支持病例中的快速瓣口开放时间(对照病例为 100 ms,支持病例为 175 ms)和快速瓣口关闭时间(对照病例为 50 ms,支持病例为 150 ms)明显长于对照病例。此外,BJUT-II VAD 支持减少了舒张期的逆行血流,并显著改变了瓣叶 WSS 的分布。
结论:综上所述,在减轻左心室负担的同时,BJUT-II VAD 可为主动脉瓣叶提供有益的生物力学状态,从而降低主动脉瓣疾病的风险。
Comput Methods Programs Biomed. 2020-12
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