Key Laboratory of Biomechanics and Mechanobiology (Beihang University), Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, Beihang University, Beijing, 100083, China.
Key Laboratory of Biomechanics and Mechanobiology (Beihang University), Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, Beihang University, Beijing, 100083, China.
Comput Methods Programs Biomed. 2024 Jun;251:108204. doi: 10.1016/j.cmpb.2024.108204. Epub 2024 Apr 26.
This study aimed to investigate the effects of lower-extremity cannulation on the intra-arterial hemodynamic environment, oxygen content, blood damage, and thrombosis risk under different levels of veno-arterial (V-A) ECMO support.
Computational fluid dynamics methods were used to investigate the effects of different levels of ECMO support (ECMO flow ratios supplying oxygen-rich blood 100-40 %). Flow rates and oxygen content in each arterial branch were used to determine organ perfusion. A new thrombosis model considering platelet activation and deposition was proposed to determine the platelet activation and thrombosis risk at different levels of ECMO support. A red blood cell damage model was used to explore the risk of hemolysis.
Our study found that partial recovery of cardiac function improved the intra-arterial hemodynamic environment, with reduced impingement of the intra-arterial flow field by high-velocity blood flow from the cannula, a flow rate per unit time into each arterial branch closer to physiological levels, and improved perfusion in the lower extremities. Partial recovery of cardiac function helps reduce intra-arterial high shear stress and residence time, thereby reducing blood damage. The overall level of hemolysis and platelet activation in the aorta decreased with the gradual recovery of cardiac contraction function. The areas at high risk of thrombosis under V-A ECMO femoral cannulation support were the aortic root and the area distal to the cannula, which moved to the descending aorta when cardiac function recovered to 40-60 %. However, with the recovery of cardiac contraction function, hypoxic blood pumped by the heart is insufficient in supplying oxygen to the front of the aortic arch, which may result in upper extremity hypoxia.
We developed a thrombosis risk prediction model applicable to ECMO cannulation and validated the model accuracy using clinical data. Partial recovery of cardiac function contributed to an improvement in the aortic hemodynamic environment and a reduction in the risk of blood damage; however, there is a potential risk of insufficient perfusion of oxygen-rich blood to organs.
本研究旨在探讨在不同水平的静脉-动脉（V-A）体外膜肺氧合（ECMO）支持下，下肢置管对动脉内血液动力学环境、氧含量、血液损伤和血栓形成风险的影响。
采用计算流体动力学方法，研究不同水平 ECMO 支持（100-40%富氧血 ECMO 供氧流量比）对各动脉分支血流率和氧含量的影响，以确定器官灌注。提出了一种新的血栓形成模型，考虑血小板激活和沉积，以确定不同 ECMO 支持水平下血小板激活和血栓形成风险。采用红细胞损伤模型探讨溶血风险。
研究发现，部分恢复心功能可改善动脉内血液动力学环境，减少导管内高速血流对动脉内流场的冲击，单位时间内进入各动脉分支的血流率更接近生理水平，改善下肢灌注。部分恢复心功能有助于降低动脉内高剪切力和停留时间，从而减少血液损伤。随着心脏收缩功能的逐渐恢复，主动脉内总体溶血和血小板激活水平降低。V-A ECMO 股动脉置管支持下，高血栓风险区域为主动脉根部和导管远端，当心脏功能恢复至 40-60%时，移至降主动脉。然而，随着心脏收缩功能的恢复，心脏泵出的缺氧血液不足以向主动脉弓前供氧，可能导致上肢缺氧。
我们开发了一种适用于 ECMO 置管的血栓形成风险预测模型，并使用临床数据验证了模型的准确性。部分恢复心功能有助于改善主动脉血液动力学环境，降低血液损伤风险；然而，存在富氧血液向器官灌注不足的潜在风险。
