Relatively frequent malformation of the abdominal wall and content: one gastroschisis in 15,000 (increasing); one omphalocele in 5,000 newborns.

Due to an abdominal wall defect in the region of the umbilicus, there is an eventration of abdominal content such as intestine, liver and other organs.
1. The eventrated organs must be reduced into the peritoneal cavity.
2. Longterm paralysis of the intestinal function in gastroschisis.
3. More than 50 % associated malformations in omphalocele, some of them life-threatening.

Unknown.

Gastroschisis: During pregnancy the non-protected intestine remains outside the abdominal cavity and undergoes severe reactive changes due to the amniotic fluid; the malformation is combined with a narrow midline cleft of different length.
Omphalocele: During pregnancy the extraembryonary celom persists and covers the intestine which does not undergo reactive changes as in gastroschisis.
In both types of malformations a normal rotation and fixation of the intestine does not take place.

There is a midline cleft of the abdominal wall located to the right of the umbilicus. The walls and the mesentery of the intestine are swollen due to an edema, covered by adherent coats, and stuck firmly together.

The anomaly consists of the sac of varying size from small to giant, initially being mostly transparent; therefore, the organs of the abdominal content are initially recognizable. In contrast to the gastroschisis not only the intestine, but the liver and other organs, too may be eventrated. The insertion of the umbilical cord is eccentricly located on the omphalocele sac, and the connection between the sac and the abdominal may be either narrow or large.

Already during pregnancy, either a volvulus or a strangulation of the eventrated intestine may occur in gastroschisis with abortion, or a short bowel syndrome due to an ischemic damage to the intestine.
Postnatally, newborns with an untreated gastroschis will die.
Severe associated anomalies may restrict survival in omphlocele, although the anomaly itself is not obligatory lethal.

If the clinical picture of both malformations is well-known, and a precise and careful clinical evaluation is perfomed in the individual case, there is no differential diagnosis.
Superficially, both malformations may be mixed up with a sternal cleft, a bladder or cloacal exstrophy (vesicointestinal fisssure); in case of a tiny omphalocele, with a variant of the normal umbilical cord insertion, which would be disastrous for the newborn in case of erroneous cord ligation.

Prenatal ultrasound for diagnosis of both malformations and as a follow-up to recognize an imminent complication (see natural history).
Immediately after birth photographs of the clinical findings and additional examinations for evaluation of associated malformations, such as cardiovascular and intestinal anomalies, Beckwith-Wiedemann syndrome with exomphalus, macroglossia and gigantism in omphalocele with the inherent danger of hypoglycaemia due to pancreatic islet cell hyperplasia; for premature or small-for-date newborns and for combined intestinal malformations in gastroschisis.

Primary closure, which is possible in more than 75 % in gastroschisis, less in omphalocele.
If primary closure is impossible, a staged silo closure should be performed: A silastic sheet is sutured to the rectus fascia which protects the intestine and allows a reduction of the residual intestine into the peritoneal cavity by gravity and by repeated suturing of the silo, and followed by secondary closure of the abdominal wall.
Postoperative care is necessary in the ICU for artificial ventilation and the beginning of the total parenteral nutrition; the latter is mainly necessary in gastroschisis for at least 1 to 2 months or even longer until the recovery of the intestinal function.

In gastroschisis, the mortality is less than 10 %; in omphalocele, 30-40 %. The mortality is due to the side-effect of parenteral nutrition in the former, and severe associated anomalies in the latter. The longterm prognosis for the gastrointestinal tract is good except for frequent occurrence of gastroesophageal reflux.