An improved model of experimental gastroschisis in fetal rabbits.

Previous animal models of gastroschisis have been associated with high mortality and variable degrees of intestinal evisceration. Using current fetal surgical techniques, an improved model of gastroschisis in fetal rabbits was developed. Twenty-eight time-mated New Zealand white rabbits underwent hysterotomies and fetal exposure on gestational day 25 (33-day gestation). Control fetuses (C) underwent fetal manipulation only. Gastroschisis fetuses (GS) had creation of right midabdominal wall defects. Twenty-five of 28 does (89%), 9 of 13 C fetuses (69%), and 18 of 22 GS fetuses (82%) survived. At the time of cesarean delivery 5 days later, GS fetuses had significantly lower body weights, intestinal lengths, and mucosa/submucosa height ratios (a measure of bowel wall edema), and significantly greater intestinal densities when compared with C fetuses (P less than .05, t test). This study demonstrates that (1) gastroschisis abdominal wall defects can be created in fetal rabbits with high survival rates; (2) experimental gastroschisis is associated with a profound decrease in fetal weight; and (3) eviscerated intestine is heavier, shorter, and thickened compared with normal control intestine, mimicking the clinical situation.