An extracorporeal system for lung assist includes a housing which includes a blood flow inlet in fluid connection with a pressurizing stator compartment, a fiber bundle compartment in fluid connection with the pressurizing stator compartment via a flow channel within the housing, and a blood flow outlet in fluid connection with the fiber bundle compartment. An impeller is rotatably positioned within the pressurizing compartment for pressurizing blood entering the pressurizing stator compartment from the blood flow inlet. The system further includes a fiber bundle positioned within the fiber bundle compartment. The fiber bundle includes a plurality of hollow gas permeable fibers. The plurality of hollow gas permeable fibers is adapted to permit diffusion of gas between blood and an interior of the hollow gas permeable fibers. The plurality of hollow gas permeable fibers is positioned such that blood flows around the plurality of hollow gas permeable fibers when flowing through the fiber bundle compartment. The plurality of hollow gas permeable fibers extend generally perpendicular to the direction of bulk flow of blood through the fiber bundle compartment from the flow channel to the blood flow outlet. The system further includes a gas inlet in fluid connection with the housing and in fluid connection with inlets of the plurality of hollow gas permeable fibers and a gas outlet in fluid connection with the housing and in fluid connection with outlets of the plurality of hollow gas permeable fibers.