Gastroschisis: Embryology, Pathogenesis, Epidemiology

Introduction Gastroschisis is a congenital anterior abdominal wall defect, adjacent and usually to the right of the umbilical cord insertion. It occurs as a small, full-thickness periumbilical cleft either immediately adjacent to the umbilicus or separated from it by a strip of skin. This results in herniation of the abdominal contents into the amniotic sac, usually just the small intestine, but sometimes also the stomach, colon, and ovaries (Figure). The abdominal wall defect is relatively small compared with the size of the eviscerated bowel, which often develops walls that are matted and thickened with a fibrous peel. Gastroschisis has no covering sac and no associated syndromes. This differentiates it from an omphalocele, which usually is covered by a membranous sac and more frequently is associated with other structural and chromosomal anomalies (Table 1). In addition, although gastroschisis may be associated with gastrointestinal anomalies such as intestinal atresia, stenosis, and malrotation, it has a much better prognosis than omphalocele.