Morphometric analysis of the lung in prolonged bronchopulmonary dysplasia.

Morphometric analysis of the lungs and heart of a male infant who died at 33 months of age of bronchopulmonary dysplasia after prematurity and respiratory distress syndrome and its treatment is presented. Alveolar internal surface area was 8.4 m2 compared to 15.3-27.8 for age-matched controls. The number of alveoli was 19 x 10(6) (123.3-172.5 x 10(6) for controls); however, the mean small airway diameter, 0.44 mm was normal, and small airway abnormalities were minimal. There was marked muscular hypertrophy of the right ventricle.