Department of Cardiothoracic Surgery, Stanford University, Stanford, California; Department of Mechanical Engineering, Stanford University, Stanford, California.
Department of Cardiothoracic Surgery, Stanford University, Stanford, California.
Ann Thorac Surg. 2019 Jul;108(1):90-97. doi: 10.1016/j.athoracsur.2019.01.053. Epub 2019 Mar 2.
Neochordoplasty is an important repair technique, but optimal anchoring position is unknown. Although typically anchored at papillary muscles, new percutaneous devices anchor the neochordae at or near the ventricular apex, which may have an effect on chordal forces and the long-term durability of the repair.
Porcine mitral valves (n = 6) were mounted in a left heart simulator that generates physiologic pressure and flow through the valves, and chordal forces were measured with Fiber Bragg Grating strain gauge sensors. Isolated mitral regurgitation was induced by cutting P2 primary chordae, and the regurgitant valve was repaired with polytetrafluoroethylene neochord with apical anchoring, followed by papillary muscle fixation for comparison. In both situations, the neochord was anchored to a customized force-sensing post positioned to mimic the relevant in vivo placement.
Echocardiographic and hemodynamic data confirmed that the repairs restored physiologic hemodynamics. Forces on the chordae and neochord were lower for papillary fixation than for the apical fixation (p = 0.003). In addition, the maximum rate of change of force on the chordae and neochordae was higher for apical fixation than for papillary fixation (p = 0.028).
Apical neochord anchoring results in effective repair of mitral regurgitation, albeit with somewhat higher forces on the chordae and neochord suture, as well as an increased rate of loading on the neochord compared with the papillary muscle fixation. These results may guide strategies to reduce stresses on neochordae as well as aid optimal patient selection.
腱索成形术是一种重要的修复技术，但最佳锚固位置尚不清楚。尽管通常锚固在乳头肌上，但新的经皮装置将腱索锚固在心室尖部或附近，这可能会影响腱索的力和修复的长期耐久性。
将猪二尖瓣（n=6）安装在左心模拟器中，该模拟器通过瓣膜产生生理压力和流量，并使用光纤布拉格光栅应变计传感器测量腱索力。通过切割 P2 初级腱索诱导孤立性二尖瓣反流，并使用聚四氟乙烯腱索进行修复，采用尖部锚固，然后进行乳头肌固定进行比较。在这两种情况下，腱索都锚固在定制的力感应柱上，以模拟相关的体内位置。
超声心动图和血流动力学数据证实，修复恢复了生理血流动力学。乳头肌固定的腱索和腱索受力低于尖部固定（p=0.003）。此外，尖部固定的腱索和腱索的力变化率最大值高于乳头肌固定（p=0.028）。
尖部腱索锚固可有效修复二尖瓣反流，尽管腱索和腱索缝线的受力略高，以及腱索的加载速率高于乳头肌固定。这些结果可能有助于指导减少腱索受力的策略，并有助于最佳患者选择。
