ECMO (Extra Corporeal Membrane Oxygenation) is a technique supporting vital functions through extracorporeal circulation, by raising blood oxygenation, reducing the blood values of carbon dioxide (CO2), increasing cardiac output and acting on body temperature. In conditions of severe respiratory and/or cardiac insufficiency, it allows to rest heart and lungs while performing their ventilation and pump functions. The most common sites for establishing peripheral ECMO are femoral artery and vein. The main goal of ECMO cannulation is to provide the least traumatic and most durable and simplified method for delivering the blood to and from the circuit. There are several ways to connect ECMO to the venous/arterial system. The present study’s aim is to analyse one connection by anastomoses and another one by cannula through a Computational Fluid Dynamics CFD) model.