Unilateral pulmonary emphysema created by ligation of the left pulmonary artery in newborn puppies.

The left pulmonary artery was ligated in 7 puppies 12 to 24 hours after birth. All were followed by periodic chest roentgenograms. At 6 months of age, ventilatory spaces, split-lung function, and static compliances were determined. Bronchograms and arteriograms were obtained, and histopathology was studied. All animals demonstrated a decrease in left lung size with gross and microscopic changes typical of chronic emphysema. There was impressive bronchial artery hypertrophy. Oxygen consumption and static compliances in the left lungs were depressed. These marked alterations in maturation, as well as the degenerative changes, are believed to be related to an impairment in the nutritive circulation of the lung.