Hypothermic lung preservation functions, six or more years later.

The functions of each lung were measured 41 and 79 months following hypothermic twenty-four four lung preservation and autotransplantation in six and four dogs respectively. Functional results were compared with long-term autotransplanted canine lungs. Compliance, total lung capacity, functional reserve capacity and ventilation of preserved lungs were similar to autotransplanted lungs, and only slightly decreased as compared with normal animals. There was no statistically significant difference between the pulmonary diffusion capacity and oxygen uptake of the preserved and autotransplanted lungs group and autotransplants alone. However, in both groups, diffusion capacity and oxygen uptake were decreased as compared with intact animals. Pulmonary hypertension was found on occlusion of the contralateral lung's artery: it was due to increased pulmonary vascular resistance. No gross narrowing of the pulmonary artery or venous anastomosis was found that could explain the increased resistance. Diffuse emphysema of various degrees was observed in all animals. This study seems to indicate that hypothermic preservation of the lung does not affect significantly the long-term functional ability of the organ, and probably will have practical value in future clinical lung transplantation.