Treatment is surgical. The bowel is untwisted, and Ladd bands and other abnormal membranous attachments are divided. The mesentery is spread out and flattened against the posterior wall of the abdomen by moving the cecum to the leftside of the abdomen. Sutures may be used to hold the bowel upstream dilation of the bowel and small, disused intestinedistally. When obstruction is complete or high grade, bilious vomiting and abdominal distention are present in thenewborn period. In lesser cases, as in “windsock” types of intestinal webs, the obstruction is partial, and symptoms aremore subtle.
Intestinal atresia presents with a history of polyhydramnios, abdominal distention and bilious vomiting in the neonatal period. If intestinal perforation is present, peritonitis and sepsis may develop.
Plain abdominal x-rays may localize the area of atresia andidentify evidence of perforation, such as free air or calcifications typical of meconium peritonitis. Duodenal atresiaappears as a double-bubble sign (gas in the stomach andenlarged proximal duodenum), with no gas distally. Atresiasof the distal intestine are characterized by longer segments ofdilated, air-filled bowel. Contrast studies are helpful if plainfilms are not sufficient. Atresia may be a complication ofmeconium ileus associated with cystic fibrosis. Laboratory evaluation for cystic fibrosis (see Chapter 137) is indicatedin cases of small bowel atresia. A complete blood count, serum electrolytes, liver functions, and amylase should bemeasured to identify dehydration, pancreatitis, and othercomplications.
The treatment of intestinal atresia is surgical, but surgery must be preceded by adequate hemodynamic stabilization of the patient. Intravenous (IV) fluids, nasogastric suction, and broad-spectrum antibiotics should be given.
Figure 129-3 Types of intestinal atresia. A, Internal web; B, Cordlike remnant connecting proximal and distal bowel; C, Interrupted bowel with V-shaped mesenteric defect; D, “Apple peel” atresia with surviving bowel spiraling around a marginal artery; E, Multiple atresias. (From Grosfeld JL, Ballantine TVN, Shoemaker R: Operative management of intestinal atresia based on pathologic findings, J Pediatr Surg 14:368–375, 1979.)
Gastroschisis is an abdominal wall defect, not involving the umbilicus, through which intestinal contents have herniated. In contrast to omphalocele, the bowel is not covered by peritoneum or amniotic membrane. As a result, prolonged contact with the amniotic fluid typically causes a thick, exudative covering (a “peel”) on the exposed bowel. Gastroschisis is not associated with extraintestinal anomalies, but segments of intestinal atresia are common. After surgical reduction of the defect, return of normal bowel function may be slow and requires prolonged parenteral nutrition for infants with long atretic segments (short bowel syndrome) and infants with a thick peel.
Omphalocele is an abdominal wall defect through the umbilicus caused by failure of the intestine to return to the abdomen during fetal life. The bowel remains within the umbilicalcord and is covered by peritoneum and amniotic membranes. This defect is associated with other congenital anomalies, especially cardiac defects, Beckwith-Wiedemann syndrome, and intestinal complications. Treatment is surgical closure, whichsometimes must be performed in stages to fit the bowel into acongenitally small abdominal cavity.