Follow-up for Vein of Galen Malformations in Children

Frequency of Office Visits

• Follow-up and monitoring of neonates prior to embolization: If newborns are stable on room air or do not have signs of worsening cardiac function, follow-up may include monthly ECGs and head ultrasounds to ensure continued stable brain, heart, and lung function. At approximately 6 months, they may benefit from an interval full brain MRI/MRA with contrast to evaluate the status of the VOGM and plan for an elective angiogram and staged embolization.
• Follow-up and monitoring after partial embolization: Infants and older children who have undergone partial embolization are typically followed pursuant to their embolization schedules. Staged embolization schedules vary according to the degree of residual flow and clinical status; 1- to 3-month intervals are typical. Patients who decompensate clinically or develop symptoms and signs of hydrocephalus require urgent evaluation.
• Follow-up after complete embolization: Infants and older children who have undergone complete embolization typically return for a follow-up visit 6 months to 1 year after the last embolization procedure. Despite complete embolization, patients may develop symptoms and signs of hydrocephalus (obstructive hydrocephalus due to VOGM thrombosis); these patients require urgent evaluation. Patients may experience persistent seizures and/or other neurological morbidity/complications, requiring long-term follow-up with a pediatric neurologist.

Frequency of Evaluations

Prior to embolization

• Monthly cranial ultrasound: Cranial ultrasonography can provide noninvasive updates on brain development and ventricular configuration to supplement clinical findings. It evaluates for the presence of venous brain injury with brain volume loss, venous hypertension, or direct VOGM mass effect causing progressive hydrocephalus. Cranial ultrasound is favored over serial MRI because it is feasible with an open fontanelle and does not require sedation for young infants.
• Supplemental MRI/MRA: If a change is suspected, cranial ultrasound can be supplemented with a sedated MRI/MRA with contrast to further evaluate the normal and pathologic anatomy.
• Timing of routine MRI studies: MRI at birth and (if the patient is stable until then) at 6 months guides initial elective embolization staging. MRI should be performed if the patient deteriorates clinically prior to age 6 months.
• Monthly ECGs: Monthly ECGs provide a trend on cardiac function to complement the clinical exam of feeding tolerance and adequate oxygen saturation.

After partial embolization

• Timing of DSA and MRI studies: At each stage of embolization, patients undergo angiographic evaluation via DSA to assess the degree of residual flow and identify potential arterial and/or venous targets for embolization. MRI studies may be performed between each stage to evaluate treatment changes. Patients who develop symptoms and signs of hydrocephalus and/or neurologic deficits should be urgently evaluated with MRI.

After complete embolization

• Timing of MRI studies: Annual follow-up MRI after significant safe reduction of the VOGM or radiographic cure of the VOGM can confirm the subsequent clinical evaluation of appropriate neurological development. It is relatively less invasive than catheter angiography and can be performed even after closure of the fontanelle.

Other Investigations Required

• Evaluation of developmental milestones: Evaluate developmental milestones with the Denver Developmental Screening Test, which may be performed by a pediatric neurologist (44).
• Long-term follow-up: Assessment of developmental milestones, neurocognitive testing, and annual MRI/MRA with contrast should be undertaken for several years.