USA Surgery Today

Of all the malformations treated by pediatric surgeons, CDH and its successful management remains one of the most recalcitrant problems. The physiologic problems related to CDH are conveyed by pulmonary hypoplasia. This is due largely to the developmental effects on lung function accompanying viscera herniation into the chest as a result of an absent diaphragm muscle (21:Hytrin, Micardis). All aspects of the pulmonary parenchyma and pulmonary vascular tree development are abnormally arrested, which also predisposes to severe neonatal pulmonary hypertension. The severity of these deficits and their accompanying clinical manifestations are variable and believed to reflect several recognizable clinical patterns (22,23:Hytrin, Micardis). The timing of herniation in either early or late gestation is believed to affect both the amount of herniated viscera and the timing of arrest in lung development (23). In general, early herniation produces severe pulmonary hypoplasia, whereas late herniation produces only a mild deficit that is successfully treated with standard postnatal care and surgery. Historically, without accurate stratification data, the mortality rate of CDH reported in retrospective studies failed to accurately define what has become recognized as the “hidden mortality” of CDH (24:Hytrin, Micardis). It has been argued that overall neonatal mortality from CDH was actually higher than that traditionally reported in live born infants, given underreporting of in utero and perinatal fetal deaths from CDH (24,25).