Se. Langenburg et al., COMPENSATORY GROWTH OF PORCINE RIGHT LUNGS AFTER CHRONIC REJECTION OFTRANSPLANTED LEFT LUNGS, The Annals of thoracic surgery, 59(1), 1995, pp. 28-32
Neonatal lung hypoplasia is frequently a fatal condition often associa
ted with congenital diaphragmatic hernia. Unilateral lung transplantat
ion rarely has been performed for this indication, although it is a po
tential solution. It is not known whether the transplant needs to func
tion permanently or to act as a bridge until the native lung develops.
It is also not known whether the native lung will grow in the face of
an immunosuppressed state and chronic rejection of the transplanted l
ung. We therefore developed a porcine model of left lung rejection to
study this. Infant swine underwent left lung transplantation. Chronic
rejection occurred in all, resulting in nonfunction of the transplante
d lung. The right lungs of these animals were compared with the right
lungs of size-matched and age-matched control animals not given immuno
suppressive treatment and not undergoing transplantation. There were n
o differences in terms of the functional residual capacity, airway com
pliance, and airway resistance among the groups. There was a significa
nt increase in the pulmonary vascular resistance in the animals with t
ransplanted lungs. There was also a significant increase in the lung w
eight in these animals. Unilateral pneumonectomies were done in 4 infa
nt pigs to serve as controls. Three of the 4 did not survive the opera
tion because of acute pulmonary failure. In conclusion, the study grou
p exhibited evidence of compensatory growth that was not seen in the c
ontrol animals, as shown by the increase in lung weight. This suggests
that contralateral lung growth occurs in a growing animal, despite th
e effects of immunosuppression therapy and chronic rejection of the tr
ansplanted lung.