Histology of the intestine in human gastroschisis—Relationship to intestinal malfunction: Dissolution of the “peel” and its ultrastructural characteristics

There are conflicting views on the pathogenesis of the intestinal malfunction seen in infants with gastroschisis. It has been variously ascribed to abnormalities of ganglion cells and smooth muscle elements, intestinal ischemia, and the “peel” which invests the serosa of the intestine. Review of the clinical and experimental literature showed only limited information on the histology of the eviscerated human intestine. In order to add to this data base, and to further investigate the pathogenesis of the intestinal malfunction from a histologic standpoint, we reviewed surgical and autopsy material from our experience with 105 neonates with gastroschisis. Ten specimens were satisfactory for evaluation from a standpoint of tissue integrity. The specific mural components of mucosa, submucosa, muscularis, and ganglion cells were examined and found to be either normal, or to show nonspecific abnormalities that varied from case to case, and were related mostly to intestinal infarction due to compromise of the gut at the site of the gastroschisis defect. In six patients, this progressed to atresia formation. The most consistent abnormalities were found in the serosal layer with its peel. Using special stains, the peel was found to be composed largely of fibrin and collagen. Based on this study, we feel that edema and ischemic changes, though often present, are much less prominent than the peel, as the leading histologic abnormality of the intestine of gastroschisis. Squamous epithelial cells were seen in the peel in four cases, suggesting that the peel had been “appliqued” onto the serosa of the herniated fetal gut. Histologic absence of peel on noneviscerated structures is also documented, indicating the role of immersion in amnion in the generation of the peel. Dissolution of the peel is documented histologically for the first time upon comparing surgical and autopsy specimens (N.D.), and sequential surgical specimens (J.R., M.F.). Electronmicroscopy of the peel is also presented for the first time with collagen having the ultrastructural characteristics of type 1 collage noted.