Gastroschisis: no myth

Insights into the etiology and embryology of gastroschisis

The development of gastroschisis has long remained an area of interest and controversy. Successive theories about its pathogenesis are herein reviewed and discussed. Two historical assumptions, that omphalocele results from a persistent umbilical hernia, and that gastroschisis does not involve the umbilical cord, are dismissed. Therefore, one can envision gastroschisis for what it is, i.e. a ruptured physiological hernia. The causal agents for this intrauterine accident to occur are yet to be determined. Further bowel damage and complications can be explained by the mesenteric insult.

Omphalocele associated with gastroschisis defect covered with skin

Omphalocele and gastroschisis are distinct malformations in many aspects. Anatomical and pathologic findings in both conditions are usually typical and very frequent. Unusual clinical presentations of some cases may contribute to clearing up questions about the embryological origins of gastroschisis and omphalocele. We describe a rare case of omphalocele associated with gastroschisis defect covered with skin.

Gastroschisis and omphalocele

It has been widely acknowledged that exomphalos and gastroschisis are two different clinical entities. Their etiology and pathogenesis, however, remain controversial. Several techniques are available for making a prenatal diagnosis of these as well as many other malformations. Some prenatal treatment is possible, but operative management is the more usual course. In most cases, of omphalocele and gastroschisis, treated either conservatively or by any kind of surgery, intensive care is mandatory to support nutrition and often ventilation as well. Enteral nutrition at an early stage during the postoperative period might lead to bouts of necrotizing enterocolitis requiring aggressive medical treatment and sometimes even operative treatment.

A comparative investigation of the bowel wall in gastroschisis and omphalocele: relation to postoperative complications

In gastroschisis the protruding bowel is generally covered by a fibrous coating as a result of prolonged exposure to amniotic fluid but no such coating is found on the exposed bowel loops in a ruptured omphalocele. In patients with gastroschisis, the postoperative course is often complicated by periods of hypoperistalsis. Based on studies of animal models of gastroschisis, various authors have suggested that the postoperative complications might be due to structural defects of the bowel wall. In our own experimental investigation of gastroschisis using chick embryos, we found no evidence of a structural defect of the bowel wall. With a view to clinical substantiation of our experimental findings, we conducted a comparative investigation of patients material, involving 10 cases of gastroschisis, 5 cases of ruptured omphalocele, and 9 cases of intact omphalocele. The investigation revealed an entirely normal structure of the bowel wall in all 10 cases of gastroschisis. On the serosa we noted an inflammation infiltrate rich in collagen fibers, frequently containing squamous cells (vernix) and lanugo. In the cases of ruptured omphalocele, the bowel wall specimens revealed a subacute inflammatory reaction. No major abnormalities were found in the bowel wall of patients with an intact omphalocele. Normal development of the autonomic nervous system was found in all patient material. Severe ischemic changes of the bowel wall were found in 4 of the gastroschisis cases and these were the 4 patients who suffered from postoperative hypoperistalsis. Thus the complications occurring during the postoperative phase of gastroschisis are most probably due to ischemic bowel damage.

The natural history of gastroschisis during fetal life: development of the fibrous coating on the bowel loops

Patients with gastroschisis have a paraumbilical defect of the anterior abdominal wall through which bowel loops protrude. These bowel loops are edematous and covered by a fibrous coating. The moment of occurrence of gastroschisis as well as the development of the fibrous coating are unknown. This prompted an investigation of 26 human embryos and fetuses with gastroschisis at various developmental stages (crown-rump length 25-240 mm) and two stillborn fetuses (gestational age 30 weeks) with gastroschisis, as well as resected material from ten newborns (gestational age 33-40 weeks) operated for gastroschisis. Progressive changes of the serosa were only noted after the 30th week of gestation and consisted of an amniotic fluid peritonitis and progressive fibrosis. The changes are in agreement with experimental data and correlate with changes in the composition of amniotic fluid. The findings prove that gastroschisis is a very early occurrence, while the fibrous coating is a late development.

Long-term follow-up of patients with gastroschisis

Long-term follow-up of children with gastroschisis has been made possible by the increased survival of these infants over the past 20 years. We have observed that children with isolated gastroschisis defects exhibit normal growth and development beyond 5 years of age without significant bowel sequelae. Infants with gastroschisis with concomitant bowel atresia or complications who require small bowel resection are at a greatly increased risk for long-term bowel problems and abdominal complaints.

Gastroschisis and omphalocele in Finland in the 1970s: prevalence at birth and its correlates

Information on liveborn and stillborn children with gastroschisis and omphalocele was collected from hospital and register sources in Finland from 1970 to 1979. The apparent prevalence of gastroschisis at birth increased from 0.77/10 000 births in 1970-4 to 1.42/10 000 in 1975-9. The prevalence of omphalocele (1.96/10 000) was unchanged during the decade. Even for gastroschisis the apparent increase in prevalence was noted for northern Finland only, while for southern Finland the prevalence has been stable during the 1970s, possibly suggesting diagnostic or reporting differences between various parts of the country. Some correlates of increased risk of gastroschisis included: low birth weight, low maternal age, urban residence, and maternal employment in commercial and sales work.

Omphalocele in half-siblings

A family is described in which half-siblings, a boy and a girl born to unrelated mothers and a phenotypically normal father, were affected with omphalocele. The suggested mode of transmission remains unclear. Prenatal diagnosis to detect an affected fetus should be offered to relatives of omphalocele-affected individuals.