DISTRIBUTION OF LUNG PRESERVATION SOLUTIONS IN PARENCHYMA AND AIRWAYS- INFLUENCE OF ATELECTASIS AND ROUTE OF DELIVERY

Background: Bronchial healing remains one of the dominant issues in lu ng transplantation. Among other factors the quality of airway protecti on during lung procurement may contribute to improve bronchial healing . Methods: Thirty-three pigs were divided into four groups: controls ( n = 6), those receiving antegrade delivery of Euro-Collins solution wi th (n = 4) and without prostacyclin (n = 9), and those receiving retro grade delivery of Euro-Collins solution (n = 14). In addition, the ate lectatic and nonatelectatic regions of the lungs from all groups were compared. After preparation and cannulation, cardioplegic solution and Euro-Collins solution for lung preservation were given simultaneously . After removal of the heart the double-lung bloc was harvested. Durin g each experiment lungs were assessed by the following methods: dye-la beled microspheres for total and regional lung perfusion, tissue water content, pulmonary artery, left atrial and left ventricular pressures , cardiac output, lung temperature, and microscopic examination. Data were expressed as mean +/- standard error of the mean. Results and Con clusions: Our data show that (1) injection of modified dye-labeled mic rospheres is a useful method to determine absolute flow in lung parenc hyma and airways, (2) determination of tissue water content is a simpl e and reproducible method to investigate the distribution of hyperosmo lar lung preservation solutions, (3) atelectasis leads to a significan t maldistribution of lung preservation solutions regardless of the rou te of delivery (0.7 +/- 0.2 versus 6.5 +/- 1.0 ml/min/gm lung wet weig ht, p = 0.0001) and a severe increase in water content (80.6% +/- 0.4% versus 79.0% +/- 0.5%, p = 0.024), (4) prostacyclin added to the pulm onary artery flush solution results in only a slight improvement in th e distribution, and (5) retrograde delivery of Euro-Collins solution t hrough the left atrium is technically feasible and seems to improve fl ow to the airways even without the addition of prostacyclin.