Modeling conduit choice for valve-sparing aortic root replacement on biomechanics with a 3-dimensional-printed heart simulator
Modeling conduit choice for valve-sparing aortic root replacement on biomechanics with a 3-dimensional-printed heart simulator
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DOI：
10.1016/j.jtcvs.2018.10.145
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发表时间：
2019-08-01
影响因子：
6
通讯作者：
Woo, Y. Joseph
中科院分区：
文献类型：
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作者：
Paulsen, Michael J.;Kasinpila, Patpilai;Woo, Y. Joseph
目的：保留瓣膜的主动脉根部置换术的最佳管道仍有争议，有几种管道变体可用，从直管移植物到Valsalva移植物。新窦重建的益处包括增强血流剖面和改善血流动力学。然而，奇怪的是，一些临床数据表明直型移植物可能具有更好的长期耐久性。在这项研究中，我们假设，直管状移植物可能有助于保持原生圆柱形位置的主动脉瓣连合径向，从而保留瓣叶接合，减少应力，并可能提高valve performance.Methods：使用3D打印，左心脏模拟器与瓣膜保留根置换模型和生理冠状动脉循环构建。从新鲜猪心解剖主动脉瓣，并重新植入直管移植物（n = 6）或Valsalva移植物（n = 6）中。将导管安装到心脏模拟器中，并收集血液动力学、超声心动图和高速视频测量数据。直型和Valsalva移植物之间的血流动力学参数和冠状动脉血流量相似，尽管前者与较低的顺应性分数、较少的连合间径向分离峰值、保留的瓣叶接合、瓣叶速度降低相关，结论：Valsalva移植物和直型移植物在总体血流动力学和冠状动脉血流量方面表现相同。然而，有趣的是，这2种管道的生物力学差异很大，直型移植物提供了更高的径向连合稳定性和瓣叶接合。需要进一步研究这些参数如何影响临床结局。
Objective: The optimal conduit for valve-sparing aortic root replacement is still debated, with several conduit variations available, ranging from straight tubular grafts to Valsalva grafts. Benefits of neosinus reconstruction include enhanced flow profiles and improved hemodynamics. Curiously, however, some clinical data suggest that straight grafts may have greater long-term durability. In this study, we hypothesized that straight tubular grafts may help maintain the native cylindrical position of the aortic valve commissures radially, resulting in preserved leaflet coaptation, reduced stresses, and potentially improved valve performance.Methods: Using 3D printing, a left heart simulator with a valve-sparing root replacement model and a physiologic coronary circulation was constructed. Aortic valves were dissected from fresh porcine hearts and reimplanted into either straight tubular grafts (n = 6) or Valsalva grafts (n = 6). Conduits were mounted into the heart simulator and hemodynamic, echocardiographic, and high-speed videometric data were collected.Results: Hemodynamic parameters and coronary blood flow were similar between straight and Valsalva grafts, although the former were associated with lower regurgitant fractions, less peak intercommissural radial separation, preserved leaflet coaptation, decreased leaflet velocities, and lower relative leaflet forces compared with Valsalva grafts.Conclusions: Valsalva grafts and straight grafts perform equally well in terms of gross hemodyanics and coronary blood flow. Interestingly, however, the biomechanics of these 2 conduits differ considerably, with straight grafts providing increased radial commissural stability and leaflet coaptation. Further investigation into how these parameters influence clinical outcomes is warranted.