LUNG RETRIEVAL FROM CADAVER DONORS WITH NONBEATING HEARTS - OPTIMAL PRESERVATION SOLUTION

Background: We have previously studied the lime course of pulmonary ce ll viability, ultrastructural damage, and adenine nucleotide metabolit es after circulatory arrest in a rat model to investigate the feasibil ity of lung retrieval for transplantation from cadavers. This study wa s designed to investigate the effect of hypothermic flush and subseque nt 4-hour storage with either modified Euro-Collins or University of W isconsin solution on lungs retrieved 4 hours after death. Methods: Nin ety-six Sprague-Dawley rats were sacrificed by intraperitoneal injecti on of pentobarbital. Control lungs were flushed immediately after sacr ifice and stored for 4 hours. Rats in the experimental groups were sac rificed, and then their lungs were either ventilated with 100% oxygen or not: ventilated for 4 hours before flushing with either Euro-Collin s or University of Wisconsin solution followed by 4-hour hypothermic s torage. At the end of the storage period, all right lungs were maintai ned at - 70 degrees C and used to determine wet-to-dry weight ratios a nd adenine nucleotide levels with high-pressure liquid chromatography. Left lungs were assessed for viability with trypan blue dye exclusion . The effect on viability of flushing with Carolina rinse solution aft er storage was also assessed. Results: The percentage of viable cells in the control group after 4-hour hypothermic storage was 74% +/- 2% i n Euro-Collins solution-flushed lungs and 78% +/- 2% in University of Wisconsin solution-flushed lungs. This result was virtually identical to that of lungs retrieved after 4 hours of in situ oxygen ventilation followed by 4 hours of hypothermic storage. Nonventilated cadaver lun gs had substantially less viability. Adenosine triphosphate levels wer e significantly higher in the control group than in the oxygen-ventila ted group, which were higher still than those in the nonventilated gro up. Adenosine triphosphate levels were consistently higher in Universi ty of Wisconsin solution-flushed lungs compared with Euro-Collins solu tion-flushed lungs in all groups. Total adenine nucleotide levels had a similar pattern. Wet-to-dry ratios were significantly lower in the c ontrol group (Euro-Collins = 6.27 +/- 0.46, University of Wisconsin = 4.63 +/- 0.07) compared with the oxygen-ventilated (Euro-Collins = 9.8 0 +/- 0.44, University of Wisconsin = 10.96 +/- 0.60) and nonventilate d (Euro-Collins = 9.44 +/- 0.26, University of Wisonsin = 11.54 +/- 1. 16; p < 0.0001) groups. Conclusions: Four hours of circulatory arrest before 4 hours of hypothermic storage had no additional adverse impact on lung viability compared with lungs subjected to 4 hours of hypothe rmic storage alone, provided nonperfused lungs were ventilated with 10 0% oxygen. Adenine nucleotide levels were well maintained in oxygen-ve ntilated cadaver lungs, more so in University of Wisconsin solution-fl ushed lungs compared with Euro-Collins solution-flushed lungs.