LUNG GROWTH AFTER TRANSPLANTATION OF AN ADULT LOBE OF LUNG INTO A JUVENILE RAT

Objective: Shortage of donor organs for children has led to the use of living related adult lung lobar transplants, It is not known how thes e lobes or the recipient remaining lung grow after such transplants, T he purpose of the present study was to assess lung growth in rat lungs up to 6 months after adult lobe transplantation into a juvenile recip ient. Methods: Right cardiac lung lobes from adult male Le,vis rats we re transplanted into the left hemithorax of juvenile (6-week-old) male Lewis rats after left pneumonectomy, Animals with appropriate control s were put to death 14 days and 6 months after transplantation. The lu ngs were fixed inflated and studied by means of quantitative morphomet ric techniques, Results: By 6 months after transplantation both the re cipient right lung and the transplanted cardiac lobe were significantl y larger than normal (p = 0.005; p = 0.001), In the recipient right lu ng this increase was due to an increase in the number of alveoli (p = 0.004) and in the transplanted cardiac lobe to an increase in size of the alveoli (p = 0.008). Conclusions: An adult lobe transplanted into a young recipient is still viable and has normal architecture after 6 months, and growth of the recipients' own lung continues, The outlook for comparable transplants in children is promising, although the huma n condition can be complicated by rejection, infection, and treatment strategies.