Effects of amnio-allantoic fluid exchange on bowel contractility in chick embryos with gastroschisis

Abstract

Background/Purpose: Intestinal damage in patients with gastroschisis is characterized by bowel wall thickening, intestinal dilatation, mesenteric shortening, and a fibrous peel. The prevention of intestinal damage in gastroschisis by amnio-allantoic fluid (AAF) exchange has been reported using histologic and macroscopic evaluation of intestines, but the effects of this treatment on bowel contractility have not been investigated. The current study was performed to determine the effect of AAF exchange on the intestinal contractility in chick embryos with gastroschisis. Methods: Thirteen-day-old fertilized chick eggs were used. Gastroschisis was created through amnio-allantoic cavity. There were 3 study groups: control group, gastroschisis-only group, and gastroschisis-plus-exchange group. The bowels were evaluated by an in vitro muscle strip technique, and the response was expressed as a percentage of the maximum acetylcholine evoked contraction (Emax) in each tissue obtained. Additionally, parasympathetic ganglion cells per 10 plexus at the intestinal wall were counted. Differences between groups were analyzed by analysis of variance (ANOVA) followed by Tukey-Kramer. Probabilities of less than 5% were considered significant. Results: The intestines were thickened and covered by fibrous peel in the gastroschisis-only group when compared with the control group and the gastroschisis exchange group morphologically. There was a statistically significant decrease in contractility in the gastroschisis-only group compared with the control group (P <.05). It exerted 42.03 ± 46.73% contraction of control group's Emax. This decrease in contractility was significantly reversed in the exchange group (P <.05; Emax value of gastroschisis plus exchange group was 71.45 ± 23.54% of control group's Emax). Although the number of ganglia per 10 plexus was 76.7 ± 4.3 in the control group, it was measured 28% less in the gastroschisis-only group (P <.05). There was no significant difference between the ganglion numbers of control and exchange groups. Conclusions: Prenatal AAF exchange treatment prevents decreased bowel contractility in gastroschisis. Gastroschisis does not affect intestinal ganglia morphology, but the number of ganglion cells decreases. AAF exchange prevents these functional and morphologic adverse effects of disease. By these findings the expectancy of a better clinical result in gastroschisis with intrauterine pretreatment by amniotic fluid exchange increases. J Pediatr Surg 37:1589-1593. Copyright 2002, Elsevier Science (USA). All rights reserved.