Optimized Mitral Annuloplasty

联系PD/PI：戈尔曼，约瑟夫 缺血性二尖瓣返流(IMR)是临床上的主要问题。我们的团队已经证明了IMR是一种 具有两个一般亚群的异质性疾病。(1)在一组中，IMR是由中度环状结构引起的 扩张和深浅的小叶捆绑。我们已经证明，这些患者最好是瓣膜置换术。 2)在第二个亚群中，IMR是严重的环状扩张(即最小的小叶拴系)的结果。这里, 环成形术已被证明是一种有效的治疗方法，前提是环仍固定在 环状空间。这些修复的致命弱点是需要更高的缝合力来缩小这些大的环状结构， 这就容易裂开。据估计，13%-42%的再手术是由环裂引起的 与手术相关的修复失败。(3-5)当局部组织的缝线保持强度为 超过了缝合线上的力。我们已经开发了新型传感器来测量环缝合力和 量化环型、大小、缝合位置、环状组织学和握力对裂开的影响 可能性。(6-9)这些研究已经从机械上证明了环的柔韧性显著减少缝合。 力，特别是在环状组织最弱的区域。这些结果表明，合并 节段环的灵活性和已知的鞍形功能优势将产生IMR特有的环 其恢复了瓣膜几何形状，同时即使在次优缝合的情况下也降低了裂开的可能性 放置。为此，设计了以下具体目标来证明这一假设：在环境中 在IMR中，新的刚性-柔性混合式瓣膜成形环能够恢复正常的瓣膜几何形状 并将环形缝合力减小到克服次优缝合效果的程度 放置位置否则会导致裂开的可能性增加。

Contact PD/PI: GORMAN, JOSEPH Ischemic Mitral Regurgitation (IMR) is a major clinical problem. Our group has demonstrated that IMR is a heterogeneous disease with two general subpopulations.(1) In one group, IMR results from moderate annular dilatation and profound leaflet tethering. We have shown these patients are best treated by valve replacement.(1, 2) In the second subpopulation, IMR is the result of severe annular dilatation (i.e. minimal leaflet tethering). Here, ring annuloplasty has been shown to be an effective treatment, provided the ring remains anchored to the annulus. The Achilles heel of these repairs is the higher suture forces required to downsize these large annuli, which predisposes to dehiscence. Ring dehiscence is estimated to underlie 13- 42% of reoperations for procedure-related repair failures.(3-5) Dehiscence occurs when the suture holding strength of the local tissue is exceeded by the force on the suture. We have developed novel transducers to measure ring suture force and quantified the effects of ring type, sizing, suture position, annular histology, and holding strength on dehiscence likelihood.(6-9) These studies have mechanistically demonstrated that ring flexibility significantly reduces suture forces, specifically in the weakest region of annular tissue. These results suggest that the incorporation of segmental ring flexibility to the already known functional benefits of saddle shape will produce IMR-specific rings that restore valve geometry while reducing dehiscence likelihood even in the setting of suboptimal suture placement. To this end, the following specific aims have been designed to prove the hypothesis: In the setting of IMR, new hybrid rigid-flexible annuloplasty rings are capable of both restoring normal valve geometry and reducing ring suture forces to a magnitude that overcomes the effect of suboptimal suture placement that otherwise would lead to an increased likelihood for dehiscence.