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

采用自体心包（TriRec）进行主动脉瓣三叶重建术是一种治疗病变主动脉瓣的新选择，与传统瓣膜置换术相比具有受益。目前没有评价TriRec手术作用的前瞻性随机试验，影响长期耐久性的因素未知。在一项前瞻性随机试验中，我们希望使用4D- Flow-磁共振成像（MRI）比较TriRec手术或生物人工瓣膜置换术后患者的主动脉血流模式。 在患有三尖瓣主动脉瓣的健康受试者中，用4D-Flow- MRI检查的升主动脉中的流动模式显示接近层流并且没有流出道阻塞。相比之下，在患病瓣膜中以及在用机械或生物假体置换瓣膜后观察到螺旋流模式、螺旋流和流速增加。这些螺旋状流动模式似乎不仅影响主动脉壁重塑，而且可能导致生物瓣膜的结构性功能障碍。我们假设TriRec手术后的血流模式比生物主动脉瓣置换术后更符合生理学。这些结果有助于理解影响TriRec瓣膜长期耐久性的机制，并有助于确定这种新型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.