[Left single-lung allotransplantation with or without bronchial artery revascularization in pigs. Development of a...

After lung transplantation, immunological mechanisms are easier to understand if the pathologist can examine larger pieces of tissues than those obtained by endoscopic biopsies. The purpose of this study was to test the experimental left-lung transplantation in the pig, performed with or without bronchial arterial revascularization and with a survival of 5 weeks. Three animals were only thoracotomised (sham-operated), ten were allotransplanted without and nine with- bronchial arterial revascularization. To optimize survival several clinical and paraclinical parameters were used: laboratory, immunological, endoscopic and flowmetric examinations. Seven of the nineteen transplanted animals survived until the fifth week. Long-term survival is possible and depends mainly on the development of pulmonary sepsis. We observed an increase of the pulmonary vascular resistances and pressures in the allo-transplanted animals. In these animals, histologic examination showed lymphoplasmocytic infiltration in the interalveolar walls and the number of ciliated epithelial cells decreased on the main and lobar bronchi. Our observations suggest that CD8 lymphocytic infiltration is predominant on the bronchi after transplantation and that rejection may occur in the pig. Class 2 DR Swine Leukocyte Antigen does not seem to be expressed on the bronchi in the allo-transplanted pig after 5 weeks. Finally, it is very difficult to demonstrate the patency of bronchial arterial grafts after 5 weeks and therefore to prove the influence of revascularization.