Prenatal diagnosis of vein of Galen aneurysmal malformations.

Vein of Galen aneurysmal malformations are rarely seen intracranial malformations. They represent less than 1% of the cerebral arteriovenous malformations. Prenatal diagnosis of an arteriovenous fistula malformation may be achieved by real-time and Doppler sonography with color flow imaging, by identifying dilated veins and arteriovenous shunts with turbulent flow. In addition, an elevated cardiac output may be observed and correlated with the magnitude of the cerebral arteriovenous shunt. The high incidence of cardiomegaly in neonates with arteriovenous malformations also suggests that high-output cardiac failure is already present in a significant number of cases during the 3rd trimester, and, therefore, treatment in utero may need to be considered to improve the hemodynamic status. In our case, all the above cardiovascular features were present during prenatal ultrasonography. The information on outcome compiled from the literature suggests that when an arteriovenous malformation is large enough to be detected prenatally, as in our case, it is likely to lead to cardiac failure either during the antenatal period or soon after birth. In this paper, we present the management of a case of 3rd-trimester diagnosis of a vein of Galen aneurysm associated with cardiac decompensation.