Leukocyte depletion results in excellent heart-lung function after 12 hours of storage

Extended preservation of the heart-lung bloc for 12 hours in a bovine model of heart-lung transplantation was achieved using donor core cooling, static hypothermic storage, and reperfusion on cardiopulmonary bypass with leukocyte-depleted (LD) blood. Orthotopic heart-lung transplantation was performed with (n = 4, LD group) or without (n = 4, control group) LD blood during cardiopulmonary bypass. Postoperative measurements of cardiopulmonary function were made at 2, 4, and 6 hours after reperfusion. Only 2 animals (50%) of the control group survived more than 2 hours, whereas all animals in the LD group survived the study period. Arterial oxygen tension on 100% oxygen was 535.63 ± 64.96 mm Hg and 146.45 ± 90.9 mm Kg in the LD and control groups, respectively, at 2 hours (p < 0.5) and 524.3 ± 73.32 and 147.9 ± 255.67 mm Hg at 6 hours. Pulmonary artery systolic pressure-to-systemic pressure ratio was 0.49 ± 0.08 and 0.62 ± 0.35 at 2 and 6 hours in the LD group. Extravascular lung water was 17.81 ± 0.02 mL/kg (control group) and 11.28 ± 9.15 mL/kg (LD group) at 2 hours. At reperfusion, the mean neutrophil count was 27 ± 27 and 764 ± 635 × 10⁹/L in the LD and control groups, respectively. This novel approach of leukocyte depletion during reperfusion after heart-lung preservation resulted in excellent cardiac and pulmonary protection.