Function and Morphology of the Canine Lung Two Years Following Immediate or Delayed Reimplantation

Pulmonary function studies were carried out on ten surviving dogs two years following left lung reimplantation. Reimplantation was carried out either immediately after lung excision or after four to six hours of lung preservation (utilizing hypothermia and hyperbaric oxygenation). During the two-year follow-up period, a slight decrease in Pao2 occurred, and alveolar arterial oxygen gradients increased. Pulmonary hypertension did not progress and autograft tidal volume and oxygen uptake were well preserved except in one animal which developed complete left bronchostenosis. At 24 months a “Hering-Breuer-like” reflex was noted in three animals. Narrowing of the left atrial anastomosis was observed in one half of the animals. The role of this narrowing in relation to graft function is discussed. At the present time, reimplantation allows more objective evaluation of lung preservation than is possible following allotransplantation.