Gartner M J, Wilhelm C R, Gage K L, Fabrizio M C, Wagner W R
Department of Surgery (Cardiothoracic) University of Pittsburgh, Pennsylvania, USA.
Artif Organs. 2000 Jan;24(1):29-36. doi: 10.1046/j.1525-1594.2000.06384.x.
The hypothesis that regions of low blood velocity in a membrane oxygenator, as predicted by computational fluid dynamics (CFD), would correspond with regions of clinical thrombotic deposition was investigated. Twenty heparin-coated oxygenators were sectioned following use in adult extracorporeal membrane oxygenation. The activated clotting time (ACT) was maintained at approximately 180 s via heparin infusion throughout the support period. Cross-sections were systematically photographed, and slides made to allow image projection upon a digitizing pad. Thrombotic deposition was traced to allow creation of a device cross-section image with an overlaid color scale representing thrombotic deposition frequency. A two-dimensional CFD model was developed to predict blood velocities throughout the oxygenator cross-section. Direct spatial comparisons were made between maps of CFD modeled blood speed and thrombotic deposition. Theoretical oxygenator design modification was performed within the CFD model to investigate flow paths which might minimize regions of low blood velocity. CFD results demonstrated that low velocity regions qualitatively matched regions with a high incidence of thrombotic deposition. Thrombotic deposition was also correlated to longer perfusion periods. This technique of coupling clinical data and CFD offers the potential to relate flow characteristics to thrombotic deposition and represents a potentially powerful new methodology for the optimization of oxygenator flow-related biocompatibility.
如计算流体动力学（CFD）所预测，膜式氧合器中血流速度较低的区域与临床血栓沉积区域相对应。在用于成人体外膜肺氧合后，将20个肝素涂层氧合器进行切片。在整个支持期内，通过输注肝素将活化凝血时间（ACT）维持在约180秒。对横截面进行系统拍照，并制作载玻片以便在数字化绘图板上进行图像投影。追踪血栓沉积情况，以创建一个带有表示血栓沉积频率的叠加颜色刻度的设备横截面图像。开发了一个二维CFD模型来预测整个氧合器横截面的血流速度。在CFD模拟的血流速度图和血栓沉积图之间进行直接的空间比较。在CFD模型内对理论氧合器设计进行修改，以研究可能使低血流速度区域最小化的流动路径。CFD结果表明，低速区域在质量上与血栓沉积高发区域相匹配。血栓沉积也与较长的灌注期相关。这种将临床数据与CFD相结合的技术有可能将流动特性与血栓沉积联系起来，代表了一种用于优化氧合器流动相关生物相容性的潜在强大新方法。
