Hastings Susan M, Deshpande Shriprasad R, Wagoner Scott, Maher Kevin, Ku David N
GWW School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA - USA.
Department of Pediatrics, Emory School of Medicine, Atlanta, GA - USA.
Int J Artif Organs. 2016 Jun 15;39(4):200-4. doi: 10.5301/ijao.5000498. Epub 2016 Jun 2.
Extracorporeal membrane oxygenation (ECMO) is a form of cardiopulmonary mechanical life support for critically ill patients. ECMO is burdened by both thrombotic and hemorrhagic complications. Recently there has been a clinical shift from roller pumps to centrifugal pumps. In this study, we report on bulk thrombus formation within pumps recovered from clinical use. We then replicate this thrombus formation in vitro.
Clinical pediatric ECMO circuits driven with the Sorin Revolution were collected from 16 patients. The location and extent of thrombus formation in the pumps were recorded. Pump heads were also tested in a laboratory circulatory loop. The location, extent, and appearance of the thrombi were recorded. Thrombi were examined histologically using Carstairs' stain.
Gross thrombus was observed in all pump heads at the stainless steel bearing at the inlet. In 19% of the pumps larger thrombi grew into the head over the cone and along the vanes. The thrombi were adherent and cohesive upon extraction. The thrombus formation was strikingly similar between the clinical pump heads and in vitro pump heads. Histology of both clinical and experimental samples exhibited a platelet-rich thrombus.
Our studies have revealed platelet-rich thrombus in clinical and in vitro circuits. The location and composition of the thrombi suggest that the exposed metal shaft was initially covered by contact activated coagulation followed by large-scale growth by rapid platelet accumulation from high shear rates at the inlet. The in vitro system may be used to further identify the mechanisms for pump thrombus and test new designs.
体外膜肺氧合（ECMO）是一种用于危重症患者的心肺机械生命支持形式。ECMO存在血栓形成和出血并发症的负担。最近，临床已从滚压泵转向离心泵。在本研究中，我们报告了从临床使用中回收的泵内大量血栓形成的情况。然后我们在体外复制这种血栓形成过程。
收集了16例使用索林Revolution驱动的临床小儿ECMO回路。记录泵内血栓形成的位置和范围。泵头也在实验室循环回路中进行了测试。记录血栓的位置、范围和外观。使用卡斯尔斯染色对血栓进行组织学检查。
在所有泵头的入口不锈钢轴承处均观察到肉眼可见的血栓。在19%的泵中，较大的血栓通过锥体并沿着叶片长入泵头。血栓在取出时具有粘附性和凝聚性。临床泵头和体外泵头的血栓形成非常相似。临床和实验样本的组织学检查均显示富含血小板的血栓。
我们的研究在临床和体外回路中均发现了富含血小板的血栓。血栓的位置和组成表明，暴露的金属轴最初被接触激活凝血覆盖，随后由于入口处高剪切率导致血小板快速聚集而大规模生长。体外系统可用于进一步确定泵血栓形成的机制并测试新设计。
