[Surgical approach on rabbit embryos. A model trial of bladder exstrophy]

We describe herein a new model of surgical approach of an early mammalian embryo. Indeed the developmental mechanisms of numerous congenital anomalies, such as bladder exstrophy, remain obscure, and progresses in their knowledge must be achieved to propose better treatments. But up to now all the successful reports in experimental models of early produced malformations concerned birds or batracians, whose development is very different from human. We used the rabbit. Twenty-five time matted does were operated at 12.5 days of gestation. Out of their 247 embryos, 99 underwent a surgical procedure. Forty-eight were injured in order to produce an exstrophy. In 18 cases, the embryo extruded from the uterine cavity and could not be reintegrated, and 2 sacs were found empty. The remaining 31 were only exteriorized. Nine additional does received intravenous teratogen at 12.5 days of gestation. In the group of operated embryos we obtained 6 full-term fetuses, one of whom had a cloacal exstrophy. No exstrophy was noted among the intact embryos, neither in the 87 fetuses submitted to the teratogen. We conclude that: it is possible to operate on an early mammalian embryo, and to obtain further growth until term and that the exstrophy we observed in one case resulted from the surgical specific procedure.