Changes of Aortic Flow Patterns detected by 4D- Flow- Magnetic Resonance Imaging after Trileaflet Reconstruction of the Aortic Valve with Autologous Pericardium compared to Prosthetic Valve Replacement with Biological Prosthesis

自体心包三叶瓣瓣膜重建术(TriRec)是一种新的治疗主动脉瓣病变的方法，与传统的瓣膜置换术相比具有明显的优势。目前还没有评估TriRec手术作用的前瞻性随机试验，影响长期耐久性的因素也是未知的。在一项前瞻性随机试验中，我们想要比较TriRec手术或生物瓣膜置换术后患者使用4D-Flow-磁共振成像(MRI)的主动脉血流模式。在患有三尖瓣的健康受试者中，用4D-Flow-MRI检查升主动脉的血流模式，几乎显示层流，没有流出梗阻。相反，在病变瓣膜和机械或生物瓣膜置换术后，可以观察到螺旋流型、湍流和流速增加。这些螺旋流型似乎不仅影响主动脉壁重构，而且可能导致生物假体的结构瓣膜功能障碍。我们推测，在TriRec手术后，血流模式将比生物主动脉瓣置换后更具生理性。这些结果有助于理解影响TriRec瓣膜长期耐用性的机制，并有助于确定这一新技术在治疗主动脉瓣疾病中的作用。

Trileaflet reconstruction of the aortic valve with autologous pericardium (TriRec) is a new treatment option for diseased aortic valves and offers benefits compared to conventional valve replacement. At the moment no prospective randomized trials evaluating the role of the TriRec procedure are available and factors contributing to long- term durability are unknown. In a prospective randomized trial, we want to compare aortic flow patterns using 4D- Flow- Magnetic Resonance Imaging (MRI) in patients either after the TriRec procedure or biological prosthetic valve replacement. In healthy subjects with tricuspid aortic valves, flow patterns in the ascending aorta, examined with 4D- Flow- MRI, show nearly laminar flow and no outflow obstruction. In contrast, helical flow patterns, turbulences and increased flow velocities are observed in diseased valves and also after valve replacement with mechanical or biological prostheses. These helical flow patterns seem to not only influence aortic wall remodeling but may contribute to structural valve dysfunction of biological prosthesis. We hypothesize that after the TriRec procedure flow patterns will be more physiological than after biological aortic valve replacement. The results can contribute to understanding mechanisms influencing long- term durability of the TriRec valve and help determine the role of this novel technique for the treatment of aortic valve disease.