SUCCESSFUL EXTENDED LUNG PRESERVATION WITH UW SOLUTION

Maximum preservation times of 4-6 hr continue to plague lung transplantation. The high-potassium colloid University of Wisconsin solution (UWS) has proved superior to the crystalloid modified Eurocollins' solution (ECS) for preservation of the liver, kidney, and pancreas. The purpose of this study was to compare UWS and ECS for extended lung preservation using a technique of combined pulmonary and bronchial artery perfusion. Simultaneous pulmonary artery and bronchial artery (via a closed aortic segment) perfusion was employed to harvest the lungs of ten mongrel dogs (wt 25-35 kg) using either UWS (n=5) or ECS (n=5) preservation solutions. Following 17 hr of cold (4-degrees-C) pulmoplegic storage, the lungs were placed in an isolated perfused working lung (IPWL) apparatus. Seven freshly harvested lungs served as a control group (CON). Lung aerodynamics and gas exchange were evaluated at standard intervals until failure of the lung on the IPWL apparatus. Time until failure (mean +/- SEM) for each group was: CON = 209 +/- 14 min; UWS = 227 +/- 26 min; and ECS = 123 +/- 29 min. Only one of the ECS lungs lasted longer than 90 min. UWS-preserved lungs displayed a gas exchange efficiency equal to the CON group and better than that in the ECS-preserved lungs (lower A-aDO2, lower intrapulmonary shunt), suggesting better protection of the alveolar capillary membrane. Although the UWS lungs were initially less compliant than the ECS lungs, at no time was there a significant difference in the total work of respiration between the two groups. We conclude that UWS provides superior protection of the alveolar capillary membrane. The aerodynamic disadvantages of UWS preservation did not effect lung survival or total work of respiration.