Cerebral vascular malformations: Case

This neonate has a vein of Galen aneurysmal malformation until proven otherwise. The severe high-output cardiac failure with a structurally normal heart and the loud cranial bruit together form the classic presentation, because the vein of Galen malformation is the commonest extracardiac cause of high-output cardiac failure in the newborn. The metabolic acidosis and the poor perfusion signal that the shunt is large and that the circulation is failing, and the priority is to support the heart while the imaging confirms the diagnosis and the retrieval is arranged. ^[4][5]

Clinical findings and assessment

The key findings are the high-output cardiac failure, the structurally normal heart on the echocardiogram, the loud cranial bruit, and the metabolic acidosis. The cranial bruit is the sign that separates an intracranial shunt from an intrinsic cardiac lesion, because it reflects the turbulent flow through the arteriovenous fistula. The metabolic acidosis and the poor perfusion reflect the steal phenomenon, in which the large shunt diverts the cardiac output away from the systemic circulation and produces a multi-organ hypoperfusion. ^[5]

The bedside assessment confirms that the airway is patent but the breathing is laboured, and the team supports the circulation with the ventilation, the fluids, and the inotropes. The differential of neonatal high-output cardiac failure with a structurally normal heart includes the vein of Galen malformation, a large systemic arteriovenous malformation such as a hepatic lesion, and a severe anaemia. The loud cranial bruit points to the intracranial shunt, and the urgent cranial ultrasound or the MRI brain with MRV will confirm the enlarged midline venous sac and the feeding choroidal arteries. ^[4][1]