A system for removing gaseous micro emboli from blood prior to oxygenation. The system including a module having a blood inlet, a blood outlet, and a port configured to provide atmospheric or sub-atmospheric pressures, and microporous hollow fibers situated in the module and fluidly coupled to the port to provide the atmospheric or sub-atmospheric pressures inside the microporous hollow fibers. The module is configured to receive the blood through the blood inlet such that the blood flows from the blood inlet to the blood outlet around outside surfaces of the microporous hollow fibers such that at least some of the gaseous micro emboli in the blood are drawn from the blood through the microporous hollow fibers by the atmospheric or sub-atmospheric pressures.