儿童主动脉瓣单叶置换术后瓣叶适应性的数值分析  

Numerical Analysis on Adaptability of Valve Leaflets after Single Aortic Valve Replacement in Children

作　　者：刘宁[1,2] 侯倩文 柳思聪 李晓 潘友联[1,2] 乔爱科 LIU Ning;HOU Qianwen;LIU Sicong;LI Xiao;PAN Youlian;QIAO Aike(Faculty of Environment and Life,Beijing University of Technology,Beijing 100124,China;Intelligent Physiological Measurement and Clinical Translation,Beijing International Base for Scientific and Technological Cooperation,Beijing 100124,China)

机构地区：[1]北京工业大学环境与生命学部,北京100124 [2]智能化生理测量与临床转化北京市国际科研合作基地,北京100124

出　　处：《医用生物力学》2021年第6期869-876,共8页Journal of Medical Biomechanics

基　　金：国家自然科学基金项目(11902011,11772015)。

摘　　要：目的探究儿童主动脉瓣单叶置换(single aortic valve replacement,SAVR)术后主动脉瓣关闭不全(aortic insufficiency,AI)的生物力学机制,并提出应对措施。方法构建理想化主动脉瓣模型及术后生长模型。改变置换瓣叶游离缘长度、瓣叶高度以及改进设计的一种凹型结构,比较不同结构尺寸对术后主动脉瓣运动同步性和关闭性能的影响。结果置换瓣叶的闭合滞后于自体瓣叶,自体瓣叶贴合于置换瓣叶游离缘下方2 mm处。术后6年出现明显AI。增加瓣叶高度不能改善术后效果,且会增加瓣叶的最大应力。增加游离缘长度10%能够改善术后效果,当游离缘增加15%,会造成主动脉瓣过长,导致主动脉瓣产生不良的贴合。凹型主动脉瓣较传统结构更有利于瓣叶对合,能够有效降低最大应力20%,效果最佳。结论儿童行SAVR术后,会使瓣叶运动不同步,对合点发生偏移,术后6年出现AI现象。建议裁剪为增加游离缘长度10%的凹型结构,不建议增加瓣叶高度。Objective To explore the biomechanical mechanism of aortic insufficiency(AI)after single aortic valve replacement(SAVR)in children and propose the corresponding countermeasures.Methods The idealized aortic valve model and postoperative growth model were constructed.By changing the length of leaflet free edge,leaflet height as well as improving the design with a concave structure,the effects of different structure dimensions on movement synchronization and closing performance of the aortic valve after surgery were compared.Results The closure of the replacement leaflet lagged behind the autologous leaflet,which fitted 2 mm below free edge of the replacement leaflet.AI occurred 6 years after operation.Increasing leaflet height could not improve the postoperative effect and would increase the maximum stress of the leaflet.Increasing free edge length by 10%could improve the postoperative outcomes,while increasing free edge length by 15%would cause the leaflet to be too long,hence resulting in a poor fit of the aortic valve.Compared with the traditional structure,the concave structure was more beneficial for closing performance of the aortic valve,and it could effectively reduce the maximum stress by 20%with the best effect.Conclusions The leaflet movement will be out of synchronization after SAVR,the point of convergence will be shifted,and AI will appear 6 years after surgery.It is recommended to use a concave structure with free edge length increased by 10%,while increasing leaflet height is not recommended.

关 键 词：主动脉瓣置换 单叶置换术 主动脉瓣关闭不全 数值分析 

分 类 号：R318.01[医药卫生—生物医学工程]