The pathogenesis of omphalocele and gastroschisis : An unsolved problem.

The embryology of gastroschisis and omphalocele remains a matter of speculation. Most authors still assume that they represent separate entities with a different pathology and embryology. In contrast, others feel that gastrochisis is simply the end-result of a ruptured omphalocele. Reviewing the current literature on the normal and abnormal embryology of the anterior abdominal wall, it becomes obvious that appropriate embryological knowledge of these processes is still missing. Animal models are not at hand that would allow clear definitions of morphological changes unique to either malformation. Nevertheless, our own observations of the pathological anatomy of these anomalies lead us to believe that the abdominal wall defects are the result of disturbed development of the embryonic umbilicus. This includes gastroschisis, which is more likely a ruptured small omphalocele than a developmental entity of its own. In our view, the common ventral abdominal wall defects fall into two main categories: (1) large omphaloceles; and (2) small omphaloceles, with gastroschisis as a subentity of this lesion.