Surgical experimental jejunoileal atresia in rat embryo

Purpose

Jejunoileal atresia represents about 40% of intestinal atresia. After surgical repair, intestinal motility disorders are burdened with the postoperative outcome, and the origin of these troubles remains unclear. To specify the physiopathologic feature of jejunoileal atresia, we developed an experimental surgical model in fetal rat.

Methods

Time-dated pregnant rats were operated on at 18 days of gestational age. Hysterotomy was performed, followed by fetal wall incision. The exteriorization of the bowel loop was obtained by saline injection; the intestine was ligated and returned to the abdominal cavity before incisions were closed. Fetal intestine was excised at day 21, after cesarean delivery.

Results

Twenty-one pregnant rats underwent operation with 90% maternal survival rate. Among the 56 fetuses successfully operated on, 49 survived (87%). In fetuses with atresia, the mean birth weight (4.5 ± 0.6 g) and the mean intestinal length (12.8 ± 1.3 cm) were significantly lower compared to sham fetuses and controls.

Conclusion

The rat model offers the advantage of a low-expense mammal model with a wide panel of probes and reagents available for the study of the gut. This model of jejunoileal atresia could be used to study the consequences of prenatal intestinal obstruction on fetal gut.