Vein of Galen aneurysmal malformation (VGAM) is a severe rare vascular anomaly whose prognosis depends on cerebral and cardiac consequences that can be hard to diagnose, let alone predict in utero. We performed an updated review to summarize current research on the genetics, ultrasound and MRI of VGAM that could help in the diagnosis and management of VGAM. Prenatal diagnosis of VGAM has greatly improved in recent years. Ultrasound allows in utero detection of VGAM in most cases now and is the best exam for prenatal cardiac evaluation. Tricuspid insufficiency is the only cardiac feature associated with poor prognosis. Cardiomegaly may indicate a risk of cardiac failure at birth and should prompt discussion of birth in a specialized facility. Ultrasound can identify constituted cerebral lesions, but MRI diagnoses early signs of cerebral hemodynamic changes, notably through the detection of pseudo-feeders. Genetic exploration should be proposed after VGAM diagnosis. Ultrasound and MRI are essential complementary tools for the diagnosis of VGAM, but also for prognostic evaluation, and provide information for the counseling of parents and optimal management of the pregnancy.
Key points What's already known about this topic?� Diagnosis of Vein of Galen aneurysmal malformation (VGAM) can be made in utero.
� Prognosis depends on cardiac and cerebral consequences.� Embolization treatment morbidity decreases with age in neonates.
What does this review add?� What to expect from ultrasound and MRI for diagnosis and prognosis.� How to manage pregnancy and delivery.� When and what genetic disorders to search for.Vein of Galen aneurysmal malformation (VGAM) is a rare congenital vascular malformation affecting less than one birth in 25,000. 1 However, it is the most common congenital vascular malformation and accounts for 30% of all pediatric vascular anomalies. 2 The onset of VGAM occurs during the choroidal stage between 8 and 11 weeks of gestation 3,4 and results from the abnormal persistence of Markowski's vein 3 or the median prosencephalic vein. Some genetic causes have been recently identified in VGAM including RASA1 and EPHB4, two genes encoding proteins essential in vascular development.
