Optimized Mitral Annuloplasty

联系人PD/PI：BERGMAN，JOSEPH 缺血性二尖瓣返流（IMR）是一个主要的临床问题。我们的团队已经证明IMR是一种 具有两个一般亚群的异质性疾病。(1)在一组中，IMR是由中度环形 扩张和严重的瓣叶栓系。我们已经证明这些患者最好通过瓣膜置换术治疗。（一、 2)在第二个亚群中，IMR是严重瓣环扩张（即瓣叶栓系最小）的结果。在这里， 环成形术已被证明是一种有效的治疗方法，只要环保持锚定在 环。这些修复的致命弱点是缩小这些大瓣环所需的较高缝合力， 容易开裂估计13- 42%的再手术是由于瓣环裂开， 程序相关的修复故障。(3-5)当局部组织的缝线固定强度低于 超过缝合线上的力。我们开发了新型传感器来测量环缝合力， 量化了成形环类型、尺寸、缝线位置、瓣环组织学和夹持强度对裂开的影响 可能性(6-9)这些研究从机械上证明了成形环的柔韧性可显著减少缝合 力，特别是在环形组织的最弱区域。这些结果表明， 节段性环的灵活性与鞍形的已知功能优势将产生IMR专用环 即使在缝合不佳的情况下，也能恢复瓣膜几何形状，同时减少裂开的可能性 安置为此，为证明这一假设，设计了以下具体目标： 在IMR中，新型混合型刚性-柔性瓣膜成形环能够恢复正常瓣膜几何形状 以及将环形缝合力减小到克服次优缝合的影响的程度 否则会导致裂开可能性增加的位置。

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.