Pathogenesis of pulmonary damage during extracorporeal perfusion.

THE CARDIOPULMONARY bypass may be followed by severe changes in the lung characterized by congestion, hemorrhage, and consolidation. These alterations often play a major role in survival after open heart surgery. 1-5 Among the explanations proposed for the changes have been hypothermia, homologous blood reaction, Filaria toxin, protein denaturation, and aggregates of substances such as fibrin which act as emboli. To further clarify this problem and to exclude emboli as a cause, the interposition of an homologous lung to act as a filter mechanism was placed in the arterial inflow line during complete cardiopulmonary bypass using hypothermia and extracorporeal circulation. In a second study, it was determined whether or not isolating the lung completely from all vascular and bronchial connections during bypass would protect it from damage during cardiopulmonary bypass and hypothermia. Materials and Methods Thirty-two healthy, young mongrel dogs of both sexes weighing between 12 and 16 kg were