Kaufmann Tim A S, Hormes Marcus, Laumen Marco, Timms Daniel L, Linde Torsten, Schmitz-Rode Thomas, Moritz Anton, Dzemali Omer, Steinseifer Ulrich
Applied Medical Engineering, Helmholtz Institute, RWTH Aachen University, Aachen, Germany.
Artif Organs. 2009 Sep;33(9):727-32. doi: 10.1111/j.1525-1594.2009.00848.x.
Approximately 100 000 cases of oxygen deficiency in the brain occur during cardiopulmonary bypass (CPB) procedures each year. In particular, perfusion of the carotid and vertebral arteries is affected. The position of the outflow cannula influences the blood flow to the cardiovascular system and thus end organ perfusion. Traditionally, the cannula returns blood into the ascending aorta. But some surgeons prefer cannulation to the right subclavian artery. A computational fluid dynamics study was initially undertaken for both approaches. The vessel model was created from real computed tomography/magnetic resonance imaging data of young healthy patients. The simulations were run with usual CPB conditions. The flow distribution for different cannula positions in the aorta was studied, as well as the impact of the cannula tip distance to vertebral artery for the subclavian position. The study presents a fast method of analyzing the flow distribution in the cardiovascular system, and can be adapted for other applications such as ventricular assist device support. It revealed that two effects cause the loss of perfusion seen clinically: a vortex under the brachiocephalic trunk and low pressure regions near the cannula jet. The results suggest that cannulation to the subclavian artery is preferred if the cannula tip is sufficiently far away from the branch of the vertebral artery. For the aortic positions, however, the cannula should be injected from the left body side.
每年在体外循环（CPB）手术过程中大约会发生10万例脑缺氧情况。特别是颈动脉和椎动脉的灌注会受到影响。流出插管的位置会影响心血管系统的血流，进而影响终末器官的灌注。传统上，插管将血液回流到升主动脉。但一些外科医生更喜欢将插管插入右锁骨下动脉。最初针对这两种方法进行了计算流体动力学研究。血管模型是根据年轻健康患者的真实计算机断层扫描/磁共振成像数据创建的。模拟在通常的CPB条件下运行。研究了主动脉中不同插管位置的血流分布，以及锁骨下位置插管尖端到椎动脉的距离的影响。该研究提出了一种快速分析心血管系统血流分布的方法，并且可适用于其他应用，如心室辅助装置支持。研究表明，临床上出现的灌注损失是由两种效应导致的：头臂干下方的涡流和插管射流附近的低压区域。结果表明，如果插管尖端离椎动脉分支足够远，则首选插入锁骨下动脉。然而，对于主动脉位置，插管应从身体左侧注入。
