Pulmonary endothelial cell modifications after storage in solid-organ preservation solutions

During lung preservation, the vascular endothelium is probably the first site of damage and these lesions are considered the main limiting factor in solid-organ preservation. In the present study, the ultrastructural changes in the endothelial cells of human pulmonary artery hypothermically stored (at 4 degrees C) for 6 and 12 h in Euro-Collins, University of Wisconsin and Ringer-lactate solutions were compared. The arteries obtained from three patients who underwent pneumonectomy were divided into 20 segments and preserved in the three solutions mentioned. The specimens, which were fixed in osmic acid, were examined using transmission electron microscopy. Transmission electron microscopy indicated that the cells stored in the University of Wisconsin solution either for 6 or 12 h were the best preserved, while the most severely damaged cells were those stored in Euro-Collins solution, even after just 6 h. The cells stored in Ringer-lactate showed an intermediate level of damage. The data from an ultrastructural grading scale, which quantified the damage to the cytoplasm, mitochondria and nucleus, were in broad agreement with the general transmission electron microscopy observations. Analysis of variance of the grading scale data showed that there were statistically significant differences between the groups after both 6 and 12 h storage (P < 0.05).