A method and system for organ evaluation and preservation for connection to an organ and for recirculation of a perfusion medium there through. The system comprises a first collection device for collection of the perfusion medium perfused through the organ and a second collection device arranged in an outlet conduit from the first collection device. A pump passes the perfusion medium from the second collection device to the organ via a conduit. A flow regulation device, such as an on-off clamp, is arranged in the outlet conduit for controlling the flow in the outlet conduit in order to maintain a constant fill of the second collection device as measured by a fluid level sensing device.
