Omphalocele

A congenital malformation (a birth defect) in which part of the intestine protrudes through a physical opening in the abdominal wall. The part of the intestine that sticks out is covered by two thin transparent membranes called the amnion (the amniotic membrane) and peritoneum (the abdominal membrane). The liver and spleen may also be within the omphalocele. An omphalocele is caused by an error in the normal embryonic development of the intestinal tract. During embryogenesis (the time during which the embryo forms), there are initially three distinct portions of the intestinal tract (the foregut, midgut and hindgut) that extend the length of the embryo. Much of the midgut is then herniated (protruded) outside the abdomen at the umbilicus (belly button). The midgut later reenters the abdomen (belly) and the opening in the abdominal wall closes. The error responsible for an omphalocele is a failure for the midgut to return and reenter the abdomen. The opening in the abdominal wall cannot close because to do so would pinch off part of the intestines. About 1 in 5,000 babies is born with an omphalocele. The omphalocele can be an isolated birth defect (all by itself). Or it may occur in children who have additional malformations as for example a congenital heart defect. Omphalocele is a characteristic malformation in certain chromosome abnormalities as the trisomy 13 (Patau) syndrome and the trisomy 18 (Edwards) syndrome. It also is seen in some genetic disorders such the Beckwith-Wiedemann syndrome. "Omphalo-" indicates a relationship to the umbilicus (the navel) and the suffix "-cele" refers to a hernia or rupture, so omphalocele literally = a hernia or rupture at the umbilicus.

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Congenital herniation of viscera into the base of the umbilical cord, with a covering membranous sac of peritoneum-amnion. The umbilical cord is inserted into the sac here, in contradistinction to its attachment in gastroschisis. SEE ALSO: umbilical hernia. SYN: amniocele, exomphalos (3), exumbilication (3). [omphalo- + G. kele, hernia]

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om·pha·lo·cele äm-'fal-ə-.sēl, 'äm(p)-fə-lə- n protrusion of abdominal contents through an opening at the navel occurring esp. as a congenital defect

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n.

an umbilical hernia.

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om·pha·lo·cele (omґfə-lo-sēl″) [omphalo- + -cele¹] protrusion at birth of part of the intestine through a large defect in the abdominal wall at the umbilicus, the protruding bowel being covered only by a thin transparent membrane composed of amnion and peritoneum. Cf. umbilical hernia. Called also amniocele, exomphalos, exumbilication, and umbilical eventration.

Omphalocele.