PM1007: Vein of Galen Malformation (VOGM) Case Report

Introduction: VOGM is an uncommon intracranial AVM which accounts for about 30% of all pediatric cerebrovascular malformations. It’s characterized by persistent embryonic arteriovenous connections between the choroidal arteries and the median prosencephalic vein-- a precursor of the mature vein of Galen (Figure 1).

Case Description: Our patient’s fetal HUS showed an AVM as a midline tubular anechoic structure superior to the thalami and contiguous with the dilated sagittal sinus. Fetal MRI head showed VOGM (ACA and PCA feeders) suggestive of diffuse supratentorial white matter injury. Fetal echocardiogram showed moderate-severe TR, moderately dilated RA and mildly dilated/hypertrophied RV with moderately diminished systolic function.

He was born at 38w0d via C/S with normal APGARs. In NICU PE was notable for macrocephaly, hyperactive precordium, 2/6 systolic murmur LUSB. Echo showed left to right shunt with RVH, diminished RV systolic function, dilation of SVC. Pre/post ductal O2 sats and vEEG were wnl. Was discharged home with digoxin and furosemide.

He never developed heart failure symptoms. At 3 months old, he successfully underwent a cerebral angiogram, coil and Onyx embolization of VOGM. On discharge, continued furosemide and will get repeat embolization at 6 months.

Discussion: VOGM has variable clinical presentation depending on specific pathophysiologic cardiopulmonary and cerebral hemodynamics. The large intracranial arteriovenous shunt can manifest as high-output cardiac failure and associated systemic hypoperfusion. Additionally, cardiac left to right shunt can lead to pulmonary hypertension resulting in right ventricular dilation and dysfunction. Left ventricle dysfunction can occur from overcompensation by pumping a normal cardiac output in addition to the shunt volume. Neurologic deficits could result from arterial steal from the cerebral circulation and intracranial venous hypertension, resulting in parenchymal ischemic/hemorrhagic injuries, encephalomalacia, seizures, and/or hydrocephalus.

Medically, VOGM is managed by decreasing the effects of the shunt by balancing pulmonary and systemic perfusion and supporting cardiac function. Those with severe heart failure require urgent neuro-intervention.

Endovascular embolization is the therapeutic standard of care and has significantly decreased mortality and reduced neurologic morbidity. It aims to occlude the arterial feeders to the malformation to reduce the shunt fraction and is deferred until approximately 3 to 5 months to allow for cerebral maturation. It’s conducted in a staged fashion to avoid the massive hemodynamic shifts associated with the instant flow reversal after occlusion of a VOGM.

After embolization, the development of hydrocephalus is closely monitored with serial neurologic assessments, including tracking of the child’s head circumference, developmental milestones, and serial ultrasonographic measurement of ventricular size. Neurocognitive difficulties with higher-level functions that are not apparent in infancy can emerge at a later age.

Conclusion: The emergence of neuro-endovascular techniques and advancement in neonatal critical care have reversed a formerly poor prognosis of VOGM. Management requires multidisciplinary care from neonatologists, cardiologists, neurologists, neurosurgeons, and interventional neuroradiologists.