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Mitral valve coaptation plate for ischemic mitral regurgitation

用于缺血性二尖瓣反流的二尖瓣接合板

基本信息

批准号：
8070058
负责人：
Zhaoming He
金额：
$ 21.67万
依托单位：
TEXAS TECH UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2010
资助国家：
美国
起止时间：
2010-05-05 至 2013-03-31
项目状态：
已结题

项目摘要

DESCRIPTION (provided by applicant): The objective of the proposed research is to prove feasibility of a novel mitral valve (MV) coaptation mechanism introduced by coaptation plate (patent pending) to prevent ischemic mitral regurgitation based on functionality and fluid-structure interaction of the MV and coaptation plate. Ischemic mitral regurgitation results from remodeling of the ischemic left ventricle, leading to displacement of the papillary muscles, annulus dilatation and consequent tethering of the MV leaflets, which restrict the closure of the mitral leaflets. Current surgical strategies include annuloplasty, repositioning of papillary muscles, chordal and leaflet manipulation, which are all based on MV coaptation mechanism of the leaflet contact and alignment. Until now, none of them offers long term reliability. Lack of effective treatment leads to 50% mitral regurgitation recurrence in 5 years. In this proposal, the PI proposes a novel MV coaptation mechanism, a concept of MV coaptation plate, to treat ischemic mitral regurgitation. It is hypothesized that ischemic mitral regurgitation can be better treated by inserting the coaptation plate into the MV orifice and utilizing new knowledge of fluid-structure interaction in an ischemic MV with the coaptation plate. The novel concept of coaptation mechanism of the coaptation plate does not require leaflets contacting each other, but induces leaflets to contact the coaptation plate as an intermediate bridge between leaflets, and seals the leaflet gap. The 2 specific aims are: 1) evaluate efficacy of the MV coaptation plate to prevent ischemic mitral regurgitation during valve closure; 2) evaluate left ventricle and MV fluid mechanics in the ischemic MV with the coaptation plate during valve opening. MV leaflet spatial configuration, gap size, pressure drop, leaflet coaptation depth and leakage during valve closure are measured and analyzed to prove efficacy of the coaptation plate. A computational fluid dynamic study on the MV, coaptation plate and left ventricle is conducted to evaluate pressure drop across the MV, shear stress, velocity, vortex pattern, and energy dissipation in the left ventricle. The novel coaptation concept of the MV introduced by the coaptation plate challenges the current MV coaptation mechanism based on leaflet contact and alignment, which depends on leaflet and annulus sizes, and chordal and papillary spatial configuration. The new coaptation mechanism of the coaptation plate requires neither touch or alignment between two MV leaflets, nor a normal or undersized annulus achieved by annuloplasty because geometry of the coaptation plate compensates leaflet displacement due to annulus dilatation and chordae tethering. Once this novel coaptation mechanism is proved to be effective and feasible, it would greatly impact current MV repair paradigms, and lead to improved surgical procedures and development of novel medical devices to prevent not only ischemic mitral regurgitation, but also mitral regurgitation of other etiologies. PUBLIC HEALTH RELEVANCE: The proposed research aims to prove feasibility of a novel mitral valve coaptation mechanism introduced by coaptation plate (patent pending) to prevent ischemic mitral regurgitation based on functionality and fluid-structure interaction of the mitral valve and coaptation plate. Once the coaptation mechanism of the coaptation plate is proved to be effective, it will greatly impact current MV repair paradigms, and lead to improved surgical procedures and development of novel medical devices to prevent mitral regurgitation with long-term reliability and decrease patient morbidity and mortality.

描述（由申请人提供）：拟定研究的目的是基于二尖瓣（MV）和接合板的功能和流体-结构相互作用，证明接合板（专利申请中）引入的新型二尖瓣（MV）接合机制的可行性，以预防缺血性二尖瓣返流。缺血性二尖瓣返流由缺血性左心室的重塑引起，导致乳头肌移位、瓣环扩张和随后的MV瓣叶栓系，这限制了二尖瓣瓣叶的闭合。目前的手术策略包括瓣环成形术、乳头肌复位、腱索和瓣叶操作，这些都是基于瓣叶接触和对线的MV接合机制。到目前为止，它们都没有提供长期的可靠性。缺乏有效的治疗导致50%的二尖瓣返流在5年内复发。在该提案中，PI提出了一种新型MV接合机制，即MV接合板的概念，用于治疗缺血性二尖瓣返流。假设通过将接合板插入二尖瓣口并利用接合板在缺血性二尖瓣中的流体-结构相互作用的新知识，可以更好地治疗缺血性二尖瓣返流。对合板的对合机制的新概念不需要瓣叶彼此接触，而是诱导瓣叶接触对合板作为瓣叶之间的中间桥，并密封瓣叶间隙。这两个具体目标是：1）评价二尖瓣对合板在瓣膜关闭过程中预防缺血性二尖瓣返流的有效性; 2）评价瓣膜打开过程中使用对合板的缺血性二尖瓣的左心室和二尖瓣流体力学。测量并分析二尖瓣瓣叶空间构型、间隙尺寸、压降、瓣叶接合深度和瓣膜闭合期间的泄漏，以证明接合板的有效性。对二尖瓣、接合板和左心室进行了计算流体动力学研究，以评价二尖瓣上的压降、左心室中的剪切应力、速度、涡流模式和能量耗散。接合板引入的二尖瓣的新型接合概念挑战了基于瓣叶接触和对线的当前二尖瓣接合机制，这取决于瓣叶和瓣环尺寸以及腱索和乳头空间构型。接合板的新接合机制既不需要两个MV瓣叶之间的接触或对齐，也不需要通过瓣环成形术实现正常或尺寸过小的瓣环，因为接合板的几何形状补偿了瓣环扩张和腱索栓系引起的瓣叶位移。一旦这种新型接合机制被证明是有效和可行的，它将极大地影响当前的二尖瓣修复范例，并导致外科手术的改进和新型医疗器械的开发，以防止缺血性二尖瓣返流，以及其他病因的二尖瓣返流。公共卫生相关性：拟定研究旨在证明由接合板（专利申请中）引入的新型二尖瓣接合机制的可行性，以基于二尖瓣和接合板的功能和流体-结构相互作用来预防缺血性二尖瓣返流。一旦证明接合板的接合机制有效，将极大地影响当前二尖瓣修复范例，并导致外科手术的改进和新型医疗器械的开发，以长期可靠地预防二尖瓣返流并降低患者发病率和死亡率。