Left lung allotransplantation in pig feasibility and transplanted lung function : Experimental Lung Transplant Group of Ospedale Maggiore of Milan

Changing attitudes to animals in research and practical considerations prompted the authors to evaluate whether the pig might be a suitable for dog and baboons for single left lung transplants. Twenty-nine paired pigs were used. The first transplants on 13 pairs (group 1) were done to adapt the lung transplant technique to pigs; later transplants on 16 pig pairs (group 2) were done to evaluate operative survival, and function and histological modifications of the transplanted lung in the absence of immunosuppressive treatment. Surgical and anesthetic techniques for both donor and recipient are described in detail. The survival rate in group 2 was 68%. Hemodynamic and blood gas changes were assessed during operation. PaO2 did not drop significantly after occluding the right pulmonary artery by an inflatable cuff placed around it; this suggests that the function of the transplanted lung was preserved. The pigs were put down on the third postoperative day. Vascular and bronchial anastomoses were patent and intact, but the transplanted lung was macroscopically and microscopically altered. Lung transplants can be performed in pigs and the transplanted lung seems to be capable of functioning immediately after the operation. Alteration in the lung after 3 days is probably due to rejection.