Bronchial heating, lung parenchymal histology, and blood gases one month after transplantation of lungs topically cooled for 2 hours in the non-heart-beating cadaver

Background: The aim of this study was to investigate, in an experimental su rvival model, the functional and morphologic results of lung transplantatio n using lungs from non-heart-beating donors. Methods: Left lungs, topically cooled to 25 degrees C for 2 hours in situ a fter 5 minutes of circulatory arrest followed by 26 minutes of unsuccessful cardiopulmonary resuscitation, were transplanted into syngeneic rats. Five weeks after the transplantation, right pneumonectomy was performed and blo od gases measured after 60 minutes. In a control group, fresh donor lungs w ere used for transplantation and comparison was made with the cadaver group and a group of normal rats after right pneumonectomy. Morphologic changes were evaluated by semiquantitative scoring of 13 different parameters to ob tain a total histologic index for each rat. Results: Computerized tomography scans of the chess made during the third p ostoperative week showed normal lung parenchyma in both groups, and at 5 we eks there were no significant differences in blood gases. The bronchial ana stomoses showed normal healing in all cases. The histologic changes in the lung parenchyma were generally mild and focal, primarily consisting of inte rstitial and perivascular mononuclear inflammation, bronchial inflammation and athelectasis. Surprisingly, the transplanted controls demonstrated the most pronounced changes, although only the difference in total histologic i ndex between groups was significant. Conclusions: Lungs from non-heart-beating donors, topically cooled in the c adaver for two hours after failed resuscitation, showed normal bronchial he aling and favorable parenchymal histology compared to transplanted control lungs 5 weeks after transplantation.