Growth and function of the replanted lung in young dogs

Autopsy findings and studies of pulmonary function, including pulmonary mechanics, air distribution, compliance, resistance, and hemodynamics in the intact animal indicate that anatomic and functional changes in the replanted growing lung do not significantly vary from those reported in adult dogs. Significant functional changes included a marked decrease in oxygen uptake and increased pulmonary vascular resistance. Since an increase in pulmonary vascular resistance was also found in animals without evidence of anatomic anomalies, pulmonary hypertension in these animals must, therefore, be related to factors other than obstruction to flow. Whether or not the increased pulmonary vascular resistance in the replanted lung may be secondary to a lack of regrowth of divided nerves is not clearly established. Lung volume distribution, as well as ventilation distribution, as evidenced by nitrogen washout data, were not significantly effected. Growth of vascular and bronchial anastomoses was slightly reduced, but the anastomotic obstructions found were due to technical error or complications rather than to failure of growth. Left pulmonary growth after replantation continued and was found to be significantly reduced only if complete obliteration of the pulmonary artery occurred.