The appliance for the oxygenation of blood (1) comprises a device (2) of the type with radial flow for extracorporeal blood oxygenation having at least an inlet fitting (4) and at least an outlet fitting (5) for the blood arranged so as to define a radial path for the blood itself, at least an inlet duct (6) and an outlet duct (7) for a work gas intended to supply oxygen to the blood and/or to remove carbon dioxide from the same, wherein the device (2) comprises transit means for the work gas placed between the inlet duct (6) and the outlet duct (7) of the type of a bundle of hollow fibers having increasing density going radially outwards,and by the fact that it comprises at least a main line (9) for the supply of the work gas to the inlet duct (6) and pressure variation means for the variation of the work gas.
