Homotransplantation of the lung in dogs, with special reference to the circulation system in the transplant.

The problem of substituting injured or diseased organs for healthy ones has been intriguing scientists for years. Animal experiments and subsequently successful transplantations of human kidneys in the fifties proved that the transplantation of organs is in reality possible, but complete success depends on the further understanding of immunological processes occurring in the recipient in response to the implanted foreign tissue. Some means of suppressing these processes and stopping the rejection of the transplanted lung must be found. The problem of transplanting the lung seems to be of particular practical interest, since the human lung is an organ that is often removed surgically, and in recent years the indications for such a procedure have increased. Quite often, however, the low respiratory reserve of the patient excludes the possibility of operation. It seems that in many of these cases the transplantation of a lung might solve the problem of respiratory deficiency and save the patient's life. The first experiments published were those of Juvenelle, Citret, Wiles, and Stewart (1951), who achieved survival after reimplanting the lung in dogs. In 1947, Demichow (1963) had experimented by transplanting the lobe of a dog's lung, but only recently have his experiments become known. Neptune, Weller, and Bailey (1953) had a year's survival after reimplantation. Hardin and Kittle (1954), after successfully transplanting the left lung, performed within a few days pneumonectomy on the opposite side and achieved survival for a further few days, thus proving that the transplanted lung was temporarily functioning sufficiently. These experiments indicated that the transplantation of animals' lungs is feasible, and that after reimplantation long-term survivals are within reach. Homotransplantation, however, has proved more difficult, due to the immunological