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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, and liver). Immediate dangers are drying of the viscera, hypothermia and dehydration from 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, including bowel atresia; chromosomal abnormalities, such as Down syndrome; and cardiac and renal anomalies, which must be identified and evaluated before surgical correction.
At delivery, the exposed viscera should be immediately covered with sterile saline-soaked sponges and then with an occlusive dressing to maintain sterility and prevent evaporation. Placing the neonate's body in a sterile bowel bag containing warm sterile saline also stops evaporation from the exposed viscera.
The infant is evaluated for associated anomalies before going to surgery. Primary closure is performed 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.
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 from the intestine being directly exposed to amniotic fluid (ie, chemical peritonitis). Infants with gastroschisis have low incidence of associated congenital anomalies other than malrotation. 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 November 2005
Content last modified November 2005
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