All circuits provide the same function, and choice will be guided by cost and training requirements, Fully integrated systems are ideal for units with low usage or high staff turnover .Bespoke systems are suited for units with complex patients or when undertaking complex types of support requiring greater versatility. These bespoke units allow the incorporation of a second oxygenator and the addition of other devices to the ECMO circuit. Some of the pumps on offer can be used as ventricular assist devices. Most of them have excellent safety and longevity records .