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Several congenital defects involve the abdominal wall, allowing protrusion of the viscera.
Omphalocele
An omphalocele is a protrusion of abdominal viscera from a midline defect at the base of the umbilicus.
In omphalocele, the herniated viscera are covered by a thin membrane and may be small (only a few loops of intestine) or may contain most of the abdominal viscera (intestine, stomach, liver). Immediate dangers are drying of the viscera, hypothermia and dehydration due to evaporation of water from the exposed viscera, and infection of the peritoneal surfaces. Infants with omphalocele have a very high incidence of other congenital anomalies (up to 70%), including
Omphalocele can be detected by routine prenatal ultrasonography; if the disorder is present, delivery should be at a tertiary care center by personnel experienced in dealing with this disorder and the other associated congenital anomalies.
At delivery, the exposed viscera should be immediately covered with a sterile, moist, nonadherent dressing (eg, medicated petrolatum gauze) to maintain sterility and prevent evaporation.
The infant is evaluated for associated anomalies before surgical repair of the omphalocele. Primary closure is done when feasible. With a large omphalocele, the abdominal cavity may be too small to accommodate the viscera. In this case, the viscera are covered by a pouch or silo of polymeric silicone sheeting, which is progressively reduced in size over several days as the abdominal capacity slowly increases, until all of the viscera are enclosed within the abdominal cavity.
Gastroschisis
Gastroschisis is protrusion of the abdominal viscera through an abdominal wall defect, usually to the right of the umbilical cord insertion.
The estimated incidence is 1 in 2000 live births (more common than omphalocele). In gastroschisis, unlike omphalocele, there is no membranous covering over the intestine, which is markedly edematous and erythematous and is often enclosed in a fibrin mat. These findings indicate long-standing inflammation due to the intestine being directly exposed to amniotic fluid (ie, chemical peritonitis). Infants with gastroschisis have low incidence of associated congenital anomalies other than malrotation. As in omphalocele, gastroschisis can be detected by prenatal ultrasonography, and delivery should take place at a tertiary care center. Surgery is similar to that for omphalocele. It often takes several weeks before GI function recovers and oral feedings can be given; occasionally, infants have long-term problems caused by abnormal intestinal motility.
Last full review/revision September 2009 by William J. Cochran, MD
Content last modified November 2010
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