The ECLS circuit consisted of a Rotaflow Maquet Centrifugal Pump (Maquet, Rastatt, Germany) and a hollow fiber membrane oxygenator (Quadrox-D Oxygenator, Maquet, Rastatt, Germany), connected with biocoated tubes. In the V-A circuit, blood was drained through femoral vein and reinfused into aorta through femoral artery. For V-V ECLS two types of cannulas were used. At the beginning, Raumedic cannulas ranging from 21 to 28 french (Raumedic AG, Germany) were employed with femoral and jugular vein cannulation. Since July 2009, Avalon Elite™ Bi-Caval Dual Lumen Catheters have become available. These specially designed dual lumen cannulas, inserted in the right internal jugular vein, permit both drainage and reinfusion of blood. In V-A ECLS, the distal perfusion of the limb could be jeopardized by the relatively large bore inflow cannula, inserted in the femoral artery at the groin: to prevent leg ischemia, we usually inserted a small shunt cannula (14 french) in the femoral artery, distally to the ECLS cannula. Heparin therapy was titrated by bedside measurement of activated partial thromboplastin time (aPTT) with Hemochron (Hemochron Jr. Sign. plus, ITC Europe, Milan, IT) every two hours. Numerical data were summarised as median and interquartile range.