Single umbilical artery and the VATER-animal model.

BACKGROUND/PURPOSE: Vascular disruption is recognized as a cause of congenital malformations. The authors analyzed the significance of single umbilical artery (SUA) in the Adriamycin-animal model to find out if it was associated with organ malformations.

METHODS

Pregnant SD rats were injected with Adriamycin intraperitoneally at a dose of 2 mg/kg on days 6 through 9 of gestation. Serial transverse sections of full-term fetuses were analyzed by light microscopy. Embryos also were removed on different gestational days during organogenesis, and serial transverse histologic sections were examined and compared with suitable controls.

RESULTS

In experimental embryos (n = 47), presence of a SUA resulted from either persistence of the primitive umbilical arteries that joined each other ventral to the hind gut to give rise to one umbilical artery or from secondary atrophy of one of the definitive umbilical arteries. Malformations such as intestinal atresia were associated with anomalous fusion between the dorsal aorta and the persistent primitive umbilical arteries.

CONCLUSIONS

SUA is a prominent feature of the Adriamycin-animal model. No obvious association was found between malformations and SUA that resulted from atrophy of one of the definitive umbilical arteries; however, it was associated with anomalies such as intestinal atresia when it resulted from persistence of the primitive umbilical arteries.