Schiavone Nicole K, Nair Priya J, Elkins Christopher J, McElhinney Doff B, Ennis Daniel B, Eaton John K, Marsden Alison L
Department of Mechanical Engineering, Stanford University, Stanford, CA, USA.
Department of Bioengineering, Stanford University, Stanford, CA, USA.
Cardiovasc Eng Technol. 2025 Feb;16(1):138-153. doi: 10.1007/s13239-024-00762-x. Epub 2024 Dec 4.
Pulmonary valve replacement (PVR) using bioprosthetic valves is a common procedure performed in patients with repaired Tetralogy of Fallot and other conditions, but these valves frequently become dysfunctional within 15 years of implantation. The causes for early valve failure are not clearly understood. The purpose of this study was to explore the impact of changing cardiac output (CO) and valve orientation on local hemodynamics and valve performance.
A 25 mm bioprosthetic valve was implanted in an idealized 3D-printed model of the right ventricular outflow tract (RVOT). The local hemodynamics at three COs and two valve orientations were assessed using 4D-Flow MRI and high-speed camera imaging.
Noticeable differences in jet asymmetry, the amount of recirculation, leaflet opening patterns, as well as the size and location of reversed flow regions were observed with varying CO. Rotation of the valve resulted in drastic differences in reversed flow regions, but not forward flow.
Flow features observed in the valve with low CO in this study have previously been correlated with calcification, hemolysis, and leaflet fatigue, indicating their potential negative impact on local hemodynamics and leaflet performance.
使用生物瓣膜进行肺动脉瓣置换术（PVR）是法洛四联症修复患者及其他病症患者中常见的手术，但这些瓣膜在植入后15年内常常出现功能障碍。早期瓣膜失效的原因尚不清楚。本研究的目的是探讨心输出量（CO）变化和瓣膜方向对局部血流动力学及瓣膜性能的影响。
将一个25毫米的生物瓣膜植入右心室流出道（RVOT）的理想化3D打印模型中。使用4D血流磁共振成像和高速摄像机成像评估三种心输出量和两种瓣膜方向下的局部血流动力学。
随着心输出量的变化，观察到射流不对称、再循环量、瓣叶开放模式以及逆流区域的大小和位置存在明显差异。瓣膜旋转导致逆流区域出现巨大差异，但顺流情况并非如此。
本研究中在低心输出量瓣膜中观察到的血流特征此前已与钙化、溶血和瓣叶疲劳相关，表明它们可能对局部血流动力学和瓣叶性能产生负面影响。
