Autoperfused working heart-lung preparation versus hypothermic cardiopulmonary preservation for transplantation

The effects of preserving the heart and lungs with an autoperfused working heart-lung preparation or simple hypothermia via cardiopulmonary bypass were studied in 18 dairy calves that had combined heart-lung transplantation. Group 1 (n = 6) served as the control group in which animals were cooled with cardiopulmonary bypass and immediately had allotransplantations. In group 2 (n = 6), cardiopulmonary function was maintained in the autoperfusion circuit for 4 hours, followed by transplantation. In group 3 (n = 6), the organs were harvested after cooling by cardiopulmonary bypass, stored in cold (4 degrees C) saline solution for 4 hours, and then transplanted. Cardiopulmonary function was compared between the three groups for 6 hours after implantation. Cardiac function was determined by the ratio of the end-systolic pressure to end-systolic dimension. Pulmonary function was evaluated by the measurement of extravascular lung water, arterial oxygenation on 100% inspired oxygen static lung compliance, and histologic lung injury score. All measurements in groups 2 and 3 were similar to those of the control group at 6 hours after implantation. One may use either the hypothermic cardiopulmonary preservation method after cardiopulmonary bypass or the autoperfused working heart-lung preparation for distant organ procurement and expect adequate cardiopulmonary function after transplantation.