Functional and histopathologic studies of primate pulmonary allografts preserved for 24 hours with a form of modified extracellular solution.
BACKGROUND: The purpose of this investigation was to evaluate the efficacy of a solution (Ep4) for long-term hypothermic pulmonary allograft preservation in a primate model using both functional and histopathologic criteria. METHODS: Twenty-seven Japanese monkeys were divided into donor group and three study groups. The animals in group I underwent acute left lung transplantation (n = 5). Group II consisted of animals which received left pulmonary allografts preserved for 24 hours by simple hypothermic immersion in Ep4 solution (n = 6). The temporary contralateral (right) pulmonary artery occlusion test was performed immediately after transplantation and on postoperative day 7 to assess lung function in the allografts. This test was also performed in the control group (group III, n = 5). The recipient animals in groups I and II were also subjected to serial open lung biopsies and bronchoscopic assessments after transplantation. RESULTS: Temporary right pulmonary artery occlusion did not show any significant differences in gas exchange capacity and pulmonary hemodynamics between groups I and II. Histopathologic examination did not show significant differences in the pulmonary allografts between groups I and II for a period of 4 weeks after transplantation. Serial bronchoscopic and histologic examinations also showed no significant differences in bronchial healing between these two groups. CONCLUSIONS: Long-term hypothermic pulmonary allograft preservation with Ep4 solution does not impair pulmonary function immediately after transplantation. The results of this study indicate that extracellular electrolyte composition solutions such as Ep4 should be subjected to clinical trials.