The femoral artery is the traditional cannulation site for peripheral venoarterial extracorporeal membrane oxygenation; nevertheless, in patients in whom access is difficult or no longer an option, alternative sites may be required. The axillary artery has been used clinically, but the hemodynamics have not been well characterized. Using a dynamic mock loop of venoarterial extracorporeal membrane oxygenation, we investigated the hemodynamics of right versus left axillary artery cannulation compared with femoral artery cannulation.

A dynamic mock loop model of adult heart failure venoarterial extracorporeal membrane oxygenation was used to test 3 cannulation sites: (1) femoral artery, (2) right axillary artery, and (3) left axillary artery. Hemodynamic data (flow and pressure waveforms) were collected at baseline and with extracorporeal membrane oxygenation support (0-3000 rpm).

Femoral artery cannulation was more effective at delivering higher mean extracorporeal membrane oxygenation flows (3.2 L/min vs 2.8 L/min) and improving femoral artery hemodynamics. Right and left axillary artery cannulation were each more effective at increasing axillary and carotid artery hemodynamics and reducing inferior vena cava pressure but increased the pressure in the ascending aorta. A small qualitative test using food coloring showed right axillary artery cannulation created a split flow down both the ascending and descending aortas, whereas left axillary artery cannulation created predominantly descending aortic flow. Femoral artery cannulation was more effective at maintaining pulsatility with increasing extracorporeal membrane oxygenation flow, whereas right and left axillary cannulation diminished pulsatility.

All 3 cannulation strategies increased flow but demonstrated potential hemodynamic tradeoffs. Further investigations are needed to better understand the hemodynamics and potential clinical impact.