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New Treatments for Intestinal Obstruction in the Newborn

Obstruction of an infant's gastrointestinal (GI) tract can occur anywhere from the esophagus to the anus. For purposes of this review, the newborn infant will be defined as an infant from birth to 30 days of age. Both congenital and acquired obstructions will be addressed. In each instance, the epidemiology, pathogenesis, clinical aspects, and management of the disorder will be considered.

Esophageal Atresia


Esophageal atresia, or interruption of the esophagus, generally occurs in association with a tracheoesophageal fistula (EA -- TEF). The most common anatomic arrangement is a blind proximal esophageal pouch that has a distal tracheoesophageal fistula. This is seen in 85% to 90% of infants who have this anomaly.

Pyloric Atresia/Stenosis


Whereas congenital obstructions of the gastric outlet are uncommon, infantile hypertrophic pyloric stenosis, an acquired condition, is one of the most commonly encountered surgical problems of infants. Studies have found an incidence of pyloric stenosis in about 1 of every 500 live births, and it is well recognized that male infants are affected more often than females. Pyloric stenosis is seen more often in caucasian children.

Duodenal Obstruction


Most obstructions of the duodenum are congenital anomalies, including atresia/stenosis, annular pancreas, and a preduodenal portal vein. Malrotation also can cause obstruction of the duodenum, which is addressed later in this review.

Congenital duodenal obstruction is seen in approximately 1 of every 10 000 births. There frequently is a history of polyhydramnios, and these infants often are either preterm or small for gestational age. There is a significant coincidence of other anomalies, including a 30% incidence of Down syndrome. Children whose duodenal obstruction is a result of an annular pancreas have as much as a 70% incidence of other anomalies.

Malrotation of the Bowel


Anomalies of intestinal rotation may be life-threatening or discovered incidental to other conditions. These anomalies result from disruption of the normal rotational process of the midgut during its return from its extracoelomic phase of development to the abdominal cavity during the fourth to tenth week of embryogenesis (Figure 2A, Figure 2B, and Figure 2C). Infants who have malrotation of the bowel often will have incomplete duodenal obstruction created by peritoneal (Ladd) bands compressing the duodenum. Because the mesentery is not broadly fixed and attached.

Jejunal/Ileal Atresia and Stenosis


Atresia or stenosis of the jejunoileal area is the diagnosis in a significant percentage of neonates who have intestinal obstruction. Atresia, or a complete congenital obstruction, is far more common than is stenosis or a partial occlusion. Reports of its incidence would seem to be on the average of 1 in 750 live births. Coexisting anomalies and familial tendencies are uncommon.

Necrotizing Enterocolitis


Neonatal necrotizing enterocolitis (NEC) is a problem that affects preterm infants predominantly. It is unclear why some children are affected and others are spared, but it may be related to compromise of the sick, stressed preterm infants mesenteric blood flow with an ischemia-reperfusion type of injury sustained by the gut. Epidemiologic data suggest that the presence of enteric feeds has a role in the pathogenesis of necrotizing enterocolitis.