Mitral Saddle Shape Preservation Improves Valvuloplasty

描述（由申请人提供）：随着经验的增加，外科医生开始将二尖瓣修复术视为因粘液瘤性瓣叶变性和缺血性二尖瓣返流（IMR）导致二尖瓣返流（MR）患者的首选治疗。然而，最近的长期研究表明，修复后严重MR的复发率比以前认为的要高得多，特别是在IMR患者中。大多数修复失败与压力有关。瓣叶曲率是瓣膜应力的重要决定因素。因此，使瓣叶曲率最大化的修复器械和技术应降低瓣膜应力并增加修复耐久性。在之前的资助周期中，我们证明了一个假设，即在绵羊修复模型中，与平坦瓣环成形术相比，鞍形瓣环成形术加重了瓣叶曲率。我们开发了软件算法，允许使用真实的三维超声心动图（rt-3DE）无创评估瓣环和瓣叶几何形状。这项工作非常富有成效，并激发了人们对瓣环成形术环设计领域和定量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的修复技术被提出来改善目前的IMR修复效果不佳。我们将使用我们新开发的RT-3DE成像算法在IMR的绵羊模型中研究这些技术。将评价每次修复对瓣叶曲率、瓣叶栓系、心室功能和耐久性的影响。这样的评估将只允许最有前途的技术在人类身上进行。公共卫生相关性：当前提案的具体目的是评价越来越多的瓣环、瓣叶和瓣环下修复技术（没有任何有效性的真实证据），以改善目前缺血性二尖瓣返流（IMR）修复的不良临床结果。我们将使用我们先前开发的3D回波成像算法在IMR修复的绵羊模型中评估这些技术的有效性。这样的评估将只允许最有前途的技术在人类身上进行。

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.