Patients on venoarterial extracorporeal membrane oxygenation undergoing ipsilateral cannulation may develop distal limb ischemia. We postulate 2 clinical questions: (1) Would contralateral cannulation have a lower distal limb ischemia rate than ipsilateral? (2) Do larger diameter arterial and venous cannulae increase the risk of distal limb ischemia independent of cannulation approach? A dynamic mock loop study investigating the potential hemodynamic benefits and risks of ipsilateral versus contralateral cannulation and cannulae size is presented.

The hemodynamics of ipsilateral versus contralateral cannulation with arterial (15F, 17F) and venous (23F, 25F) cannulae combinations over pump speeds (0-3000 rpm) delivering 0 to 3.5 L/min extracorporeal membrane oxygenation flow was evaluated in an adult heart failure dynamic mock loop.

In the dynamic mock loop, contralateral cannulation was more effective than ipsilateral at increasing flow and decreasing pressure in both limbs. Increasing arterial cannula size from 15F to 17F enabled higher extracorporeal membrane oxygenation flows but at the expense of greater intravascular obstruction. Venous cannula size (23F, 25F) had no effect on limb hemodynamics.

Our dynamic mock loop findings are consistent with reported Extracorporeal Life Support Organization Registry data and others, while also suggesting added hemodynamic benefits of venoarterial extracorporeal membrane oxygenation using a contralateral approach with the potential for better clinical outcomes.