Mitral Saddle Shape Preservation Improves Valvuloplasty

描述(由申请人提供)：随着经验的增加，外科医生已开始将二尖瓣修补术视为由于粘液瘤样叶变性和缺血性二尖瓣反流(IMR)而导致的二尖瓣反流(MR)患者的首选治疗方法。然而，最近的长期研究表明，修复后显着MR的复发率比以前认为的要高得多，特别是在IMR患者中。大多数修复失败都与压力有关。瓣叶曲率是瓣膜应力的重要决定因素。因此，最大限度地提高瓣叶曲率的修复装置和技术应该减少瓣膜应力，增加修复耐久性。在之前的资金周期中，我们在绵羊修复模型中证明了鞍形瓣环成形术与扁平瓣环成形术相比，能够加强小叶弯曲的假说。我们已经开发了软件算法，允许使用实时三维超声心动图(RT-3DE)来非侵入性地评估环状和叶状几何形状。这项工作卓有成效，激发了人们对瓣膜成形术环设计和定量RT-3DE成像领域的极大兴趣。我们的具体目标是评估越来越多的复杂修复技术被提出，以改善目前IMR修复效果不佳的情况。我们将使用我们最新开发的RT-3DE成像算法在IMR的绵羊模型中研究这些技术。每一次修复都将评估其对瓣叶弯曲、瓣叶系留、心功能和耐用性的影响。这样的评估将只允许在人类身上执行最有希望的技术。公共卫生相关性：本提案的具体目的是评估越来越多的环状、瓣叶和环下修复技术被提出(没有任何真正的有效性证据)，以改善目前缺血性二尖瓣反流(IMR)修复的糟糕临床结果。我们将使用我们之前开发的3D回声成像算法在绵羊IMR修复模型中评估这些技术的有效性。这样的评估将只允许在人类身上执行最有希望的技术。

DESCRIPTION (provided by applicant): As experience has increased, surgeons have come to view mitral valve repair as the treatment of choice in patients with mitral regurgitation (MR) due to myxomatous leaflet degeneration and ischemic mitral regurgitation (IMR). However, recent long-term studies have indicated that the recurrence of significant MR after repair is much higher than previously believed, particularly in patients with IMR. The majority of repair failures are stress related. Leaflet curvature is an important determinant of valve stress. Therefore, repair devices and techniques which maximize leaflet curvature should reduce valvular stress and increase repair durability. During the previous funding cycle we proved the hypothesis that saddle shaped annuloplasty accentuates leaflet curvature when compared to flat annuloplasty in an ovine repair model. We have developed software algorithms that allow the use of real- time three dimensional echocardiography (rt-3DE) to non-invasively assess annular and leaflet geometry. This work has been very productive and has stimulated great interest in both the field of annuloplasty ring design and the field of quantitative rt-3DE imaging. Our specific aim is to evaluate the growing number of complex repair techniques being proposed to improve the currently poor results of IMR repair. We will study these techniques in an ovine model of IMR using our newly developed rt-3DE imaging algorithms. Each repair will be evaluated regarding its effect on leaflet curvature, leaflet tethering, ventricular function and durability. Such an assessment will allow only the most promising techniques to be performed in humans. PUBLIC HEALTH RELEVANCE: The specific aim of the current proposal is to evaluate the growing number of annular, leaflet and subannular repair techniques being proposed (without any true evidence of efficacy) to improve the currently poor clinical results of ischemic mitral regurgitation (IMR) repair. We will evaluate the efficacy of these techniques in an ovine model of IMR repair using our previously develop 3D echo imaging algorithms. Such an assessment will allow only the most promising techniques to be performed in humans.