Influence of cannula positioning on brain injury during extracorporeal membrane oxygenation

Background: In veno-arterial extracorporeal membrane oxygenation (V-A ECMO), a patient is cannulated using either an atrio-aortic technique (central type ECMO; cECMO) or a femoro-femoral technique (peripheral type ECMO; pECMO). The direction of the pump flow at the aortic arch is anterograde from the ascending aorta in cECMO and retrograde from the descending aorta in pECMO. Hemodynamic differences from the position of the cannulas may influence the brain differently. To evaluate the effect of ECMO cannula positioning on the brain, hemodynamic data and plasma biomarkers were collected. Methods: Eight pigs were randomly divided into the cECMO group (n=4) or pECMO group (n=4). ECMO was administered for 6 hours at a pump flow rate based on the mean flow of the ascending aorta. Mean arterial pressure (MAP), mean arterial flow (MAF), energy equivalent pressure (EEP), and surplus hemodynamic energy (SHE) were measured in the brachiocephalic artery every 30 minutes. During ECMO treatment, plasma was collected for analysis of interleukin-6 (IL-6), S100B, glial fibrillary acidic protein (GFAP), and neuron-specific enolase. The data were analyzed using the Mann-Whitney U tests, and repeated measures ANOVAs; significance was set at P<0.05. Results: MAP and EEP at 1 and at 3 hours, MAF at all measured times, and SHE at 1 hour and 6 hours were significantly higher in the pECMO group. There was no significant difference in the levels of brain injury biomarkers between cECMO and pECMO groups. Conclusions: The hemodynamic data showed that pECMO was superior to cECMO. Based on the biomarker data, neither pECMO nor cECMO for 6 hours caused evidence of brain injury.