title: Etiology of intestinal damage in gastroschisis. I: Effects of amniotic fluid exposure and bowel constriction in a fetal lamb model.
abstract: Gastroschisis is often complicated by damage to the herniated small bowel, resulting in motility and absorption disturbances and occasional intestinal necrosis and atresia. To study the pathophysiology of this process, a model of gastroschisis was developed in fetal lambs. At 80 days' gestation, the anterior abdominal wall was partially excised to create a small peritoneal cavity, and the small bowel was extruded through a Silastic ring to create a defect of uniform size. In one experimental group, a tie was placed around the herniated bowel at the level of the abdominal wall to provide gradual constriction as the fetus grew. In a second group, no tie was placed. Control animals had a simple laparotomy and no abdominal wall defect; some also had a constrictor placed around the base of the bowel. The animals were delivered near term, and the bowel was evaluated histologically and by an in-vitro bowel motility assay. Histologic examination showed normal ganglion cells in all groups and no evidence of ischemic injury. A fibrous peel was seen only in bowel exposed to amniotic fluid, with or without a constrictor. Lymphatic and venous dilation, smooth-muscle thickening, and focal mucosal blunting were seen in bowel subjected to chronic obstruction by a constrictor, regardless of whether it was exposed to amniotic fluid. Both constriction of the bowel and amniotic fluid exposure were associated with a decrease in motility; these two effects were independent and additive.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Division of Pediatric Surgery, University of California, San Francisco.
authors.forename: J C
authors.initials: JC
authors.lastname: Langer
authors.forename: M T
authors.initials: MT
authors.lastname: Longaker
authors.forename: T M
authors.initials: TM
authors.lastname: Crombleholme
authors.forename: S J
authors.initials: SJ
authors.lastname: Bond
authors.forename: W E
authors.initials: WE
authors.lastname: Finkbeiner
authors.forename: C A
authors.initials: CA
authors.lastname: Rudolph
authors.forename: E D
authors.initials: ED
authors.lastname: Verrier
authors.forename: M R
authors.initials: MR
authors.lastname: Harrison
mesh_terms: D000009:Abdominal Muscles / Q000002:abnormalities* / Q000196:embryology; D000653:Amniotic Fluid / Q000502:physiology*; D000818:Animals; D002908:Chronic Disease; D005260:Female; D005315:Fetal Diseases / Q000209:etiology / Q000503:physiopathology*; D005769:Gastrointestinal Motility / Q000502:physiology; D006555:Hernia, Ventral / Q000196:embryology / Q000503:physiopathology*; D007410:Intestinal Diseases / Q000209:etiology / Q000503:physiopathology*; D007415:Intestinal Obstruction / Q000196:embryology / Q000503:physiopathology; D011247:Pregnancy; D012756:Sheep; D013997:Time Factors