Vein of Galen Aneurysmal Malformation and Its Varied Outcomes: An Updated Literature Review

Vein of Galen aneurysmal malformation (VGAM) is a rare congenital arteriovenous malformation of cerebral blood vessels with an incidence of approximately 1 in 25,000 live births. This embryonic malformation results from an abnormal arteriovenous connection between the primitive choroidal arteries and the median prosencephalic vein of Markowski. Though it occurs between the 6th and 11th weeks of gestation, prenatal diagnosis is possible only in the second or third trimester due to its slow growth. If left untreated, this significant shunting results in a substantial vascular steal phenomenon and also leads to cardiac failure, hydrops, and perinatal death. Prenatally diagnosed VGAM carries a poor prognosis when associated with cardiac failure or cerebral damage. Prenatal diagnosis is done by ultrasound complemented by magnetic resonance imaging of the fetal brain, while postnatal confirmation is by magnetic resonance angiography. Digital subtraction angiography is considered the gold standard for the evaluation of angioarchitecture. Though spontaneous resolution of VGAM has been rarely reported in the literature, the introduction of endovascular embolization techniques has paved the way to successful treatment of VGAM, with the potential of minimizing mortality and maximizing favorable neurodevelopment outcomes. In this study, we report three cases of prenatally diagnosed VGAM and their varied outcomes, wherein one infant had a spontaneous resolution of VGAM with normal neurodevelopment, another infant had a stormy postnatal course followed by endovascular embolization and normal neurodevelopment, while the third neonate succumbed to the effects of VGAM. We also provide a comprehensive review of literature elaborating the current understanding and management of VGAM, etiopathogenesis, classification, tools of prenatal detection, clinical characteristics, and available prenatal and postnatal treatment options.