CANINE LUNG TRANSPLANTATION AFTER MORE THAN 24 HOURS OF NORMOTHERMIC PRESERVATION

Background: Consistent clinical results have not been achieved when lu ng preservation times exceed 6 hours. The aim of this study was to use an alternative normothermic autoperfusion technique for lung preserva tion and transplantation. Methods: In six paired dogs, donor lungs wer e removed, along with the heart, liver, pancreas, duodenum, and both k idneys, and were preserved for 24 to 33 hours in a normothermic autope rfused multiple organ block. Orthotopic left lung transplantation was performed at the end of the preservation period. Results: Lung functio n was good during the preservation period. With a gas mixture of 50% O -2 + 3% CO2 + 47% N-2 delivered to the multiorgan block, arterial oxyg en tension ranged from 331 +/- 19 to 383 +/- 8 mm Hg; carbon dioxide t ension ranged from 18 +/- 5 to 32 +/- 5 mm Hg; and pH ranged from 7.36 +/- 0.02 to 7.45 +/- 0.08. After transplantation, the dogs were kept anesthetized and ventilated for 24 hours with the same gas mixture. Th e opposite pulmonary artery was occluded 0 to 6 hours after transplant ation. Arterial blood pressures were stable after surgery. Arterial ox ygen tension was maintained between 205 +/- 39 and 320 +/- 57 mm Hg, a nd arterial carbon dioxide tension was maintained between 23 +/- 2 and 34 +/- 2 mm Hg. Lung tissue wet/dry weight ratio was 4.94 +/- 0.17 af ter preservation; this ratio did not differ from that found in normal controls (4.91 +/- 0.10). Conclusions: This study shows that the lungs were well preserved for more than 24 hours of preservation when the n ormothermic multiorgan block preparation was used. The transplanted le ft lung was able to support the anesthetized dog after the opposite pu lmonary artery was occluded.