Endothelial and Hemodynamic Function in a Large Animal Model in Relation to Different Extracorporeal Membrane Oxygenation Cannulation Strategies and Intra-Aortic Balloon Pumping

Background: The use of simultaneous veno-arterial extracorporeal membrane oxygenation (ECMO) with or without an Intra-Aortic Balloon Pump (IABP) is a widely used tool for mechanical hemodynamic support. Endothelial function, especially in relation to different cannulation techniques, is rarely investigated in the setting of extracorporeal life support (ECLS). In this study, we analyzed endothelial function in relation to hemodynamic and laboratory parameters for central and peripheral ECMO, with or without concomitant IABP support in a large animal model to gain a better understanding of the underlying basic mechanisms.

Methods: In this large animal model, healthy female pigs with preserved ejection fraction were divided into the following groups related to cannulation strategy for ECMO and simultaneous IBAP support: control (no ECMO, no IABP), peripheral ECMO (pECMO), central ECMO (cECMO), pECMO and IABP or cECMO and IABP. During the experimental setting, the blood flow in the ascending aorta, left coronary artery and arteria carotis was measured. Afterwards, endothelial function was investigated after harvesting the right coronary artery, arteria carotis and renal artery. In addition, laboratory markers, such as creatine kinase (CK), creatine kinase muscle-brain (CK-MB), troponin, creatinine and endothelin were analyzed.

Results: The blood flow in the ascending aorta and the left coronary artery was significantly lower in all discussed experimental settings compared to the control group. Of note, the cECMO cannulation strategy generated favorable hemodynamic circumstances with higher blood flow in the coronary arteries than pECMO regardless of flow circumstances in the ascending aorta. The concomitant usage of IABP did not result in an improvement of the coronary blood flow, but partially showed a negative impact on the endothelial function of coronary arteries in comparison to the control. These findings correlate to higher CK/CK-MB levels in the setting of cECMO + IABP and pECMO + IABP.

Conclusions: The usage of mechanical circulatory support with concomitant ECMO and IABP in a large animal model might have an influence on the endothelial function of coronary arteries while not improving the coronary artery perfusion in healthy hearts with preserved ejection.