Bicuspid aortic valves undergo excessive strain during opening: A simulation study
Bicuspid aortic valves undergo excessive strain during opening: A simulation study
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DOI：
10.1016/j.jtcvs.2012.05.032
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发表时间：
2013-06-01
影响因子：
6
通讯作者：
Sugiura, Seiryo
中科院分区：
文献类型：
--
作者：
Katayama, Susumu;Umetani, Nobuyuki;Sugiura, Seiryo
目的：本研究的目的是检查的形态特征的二叶式主动脉瓣的疾病进展的影响，通过比较运动，应力/应变分布，和正常和狭窄的三尖瓣的血流量使用模拟models.Methods：二叶式，狭窄的三尖瓣连合融合或增厚的小叶，和正常的主动脉瓣与内部血流建模。采用流固耦合有限元分析方法研究了主动脉瓣叶的血流和运动，并计算了心动周期内的应力/应变（曲率）分布。为了模拟疾病的进展，我们修改了局部厚度的小叶弯曲应力高于threshold.Results：跨瓣压力梯度是更大的二尖瓣狭窄的三尖瓣相比，具有类似的瓣膜面积。狭窄的三尖瓣和二尖瓣的弯曲应变（曲率）均增加，但在二尖瓣中观察到更大的增加，并且这集中在融合瓣叶的中线上。在疾病进展分析中，狭窄的严重程度增加，只有在二叶式主动脉瓣模型中的瓣膜面积和压力gradient.Conclusions：二叶式瓣膜的特征形态在心室射血过程中产生过度的弯曲应变的小叶。这种机械应力可能是导致这种疾病快速进展的原因。
Objective: The objective of this study was to examine the influence of the morphologic characteristics of the bicuspid aortic valve on its disease progression by comparing the motion, stress/strain distribution, and blood flow of normal and stenotic tricuspid valves using simulation models.Methods: Bicuspid, stenotic tricuspid with commissural fusion or thickened leaflet, and normal aortic valves were modeled with internal blood flow. Blood flow and the motion of aortic valve leaflets were studied using fluid-structure interaction finite element analysis, and stress/strain (curvature) distributions were calculated during the cardiac cycle. To mimic disease progression, we modified the local thickness of the leaflet where the bending stress was above a threshold.Results: Transvalvular pressure gradient was greater in the bicuspid valve compared with the stenotic tricuspid valve with a similar valvular area. The bending strain (curvature) increased in both stenotic tricuspid and bicuspid valves, but a greater increase was observed in the bicuspid valve, and this was concentrated on the midline of the fused leaflets. During disease progression analysis, severity of the stenosis increased only in the bicuspid aortic valve model in terms of valvular area and pressure gradient.Conclusions: The characteristic morphology of the bicuspid valve creates excessive bending strain on the leaflets during ventricular ejection. Such mechanical stress may be responsible for the rapid progression of this disease.