Transcatheter Valve Underexpansion Limits Leaflet Durability: Implications for Valve-in-Valve Procedures

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• 作者：Caitlin Martin ; Wei Sun
• 关键词：Valve ; in ; valve ; Transcatheter aortic valve ; Stent underexpansion ; Soft tissue fatigue damage ; Finite element analysis
• 刊名：Annals of Biomedical Engineering
• 出版年：2017
• 出版时间：February 2017
• 年：2017
• 卷：45
• 期：2
• 页码：394-404
• 全文大小：
• 刊物类别：Biomedical and Life Sciences
• 刊物主题：Biomedicine, general; Biomedical Engineering; Biological and Medical Physics, Biophysics; Classical Mechanics; Biochemistry, general;
• 出版者：Springer US
• ISSN：1573-9686
• 卷排序：45

文摘

Transcatheter aortic valve (TAV) implantation within a failed bioprosthetic valve is a growing trend for high-risk patients. The non-compliant stent of the previous prosthesis may prevent full expansion of the TAV, which has been shown to distort the leaflet configuration, and has been hypothesized to adversely affect durability. In this study, TAV leaflet fatigue damage under cyclic pressurization in the setting of stent underexpansion by 0 (fully expanded), 1, 2 and 3 mm was simulated using finite element analysis to test this hypothesis. In the 2 and 3 mm underexpanded devices, the TAV leaflets exhibited severe pin-wheeling during valve closure, which increased leaflet stresses dramatically, and resulted in accelerated fatigue damage of the leaflets. The leaflet fatigue damage in the 1 mm underexpanded case was similar to that in the fully expanded case. Clinically a range of 10–15% underexpansion is generally considered acceptable; however, it was observed in this study that ≥2 mm (≥9.1%) underexpansion, will significantly impact device durability. Further study is necessary to determine the impact of various deployment conditions, i.e. non-uniform and non-circular deployments and different implantation heights, on differing TAV devices, but it is clear that the normal TAV leaflet configuration must be preserved in order to preserve durability.