Diaphragmatic Hernia

Congenital diaphragmatic hernia (CDH), with an incidence of approximately 1 in 3000 births, occurs secondary to defective fusion of the pleuroperitoneal membranes during embryonic development. The most common form is the posterolateral hernia through the foramen of Bochdalek, with a left-to-right ratio of approximately 8:1. The space-occupying effect of the bowel during pulmonary development results in hypoplasia of the ipsilateral lung. This process also may cause hypoplasia to a lesser degree of the contralateral lung, secondary to severe mediastinal shift. Bohn and co-workers assessed alveolar number by postmortem morphometric analysis of five infants who died after surgical repair for CDH. A severe reduction in alveolar number was noted in both the ipsilateral and contralateral lung, although the changes in the ipsilateral lung were more pronounced.