Preparation for Surgery for Vein of Galen Malformations in Children

Indications for Procedure

Endovascular embolization aims to minimize flow across the AV shunt in VOGM to minimize vascular steal in the cerebral vasculature, mitigate cerebral venous hypertension, improve cardiac and other organ function, and achieve normal cerebral development (39,44).

• Considerations: Treatment decisions and timing should depend on the patient’s symptoms and concern for future neurological impairment.
• Risks and benefits: The goal of treatment should weigh the risk of procedures and the benefits of radiographic cure, compared to achieving an asymptomatic physiological state.

Treatment decisions in neonates

In neonates, pursue medical management to achieve cardiovascular stabilization and gain time — the risk of complications with treatment are greater in the neonatal period compared to even a few months later (44). Treatment decisions can be guided by The Bicêtre Neonatal Evaluation Score, one method of comprehensively evaluating the overall morbidity and recoverability of organ function (24).

• Neonates with severe presentation: Endovascular embolization may not be indicated in neonates presenting with severe injury to multiple organs that are refractory to medical management; palliative care may be pursued (24).
• Emergent intervention: Emergency embolization may be indicated in symptomatic neonates who are not stable despite (or stagnate in response to) medical management or in those who experience clinical deteriorations (24,44).
• Delay of definitive treatment: Intervention can be delayed in neonates who are stable with medical management, or in those who are relatively asymptomatic. Embolization may be pursued with a lower risk profile by age 5 months (24). Patients who fail to improve with medical management or cannot tolerate forms of medical management (for example, patients who experience significant side effects of medications) should be considered for urgent intervention.

Treatment decisions in older patients

Treatment of infants and older children should aim to prevent the consequences of hydrocephalus, avoid the need for CSF diversion, and minimize developmental delay (24,44).

Preoperative Orders

Stabilization and robust evaluation are important prior to intervention.

Anesthetic Considerations

• Important anesthetic considerations: The potential for high-output heart failure in patients with VOGM is an important consideration for the anesthesiologist; patients may already be on various medications including diuretics, inotropes, and vasodilators (74).

Devices to be Implanted

• Embolization agents: Embolization may be achieved via coils (arterial or venous) or liquid embolic agents such as polymerizing acrylate glue or Onyx (75,76).
• Shunts: For some patients presenting with hydrocephalus, CSF diversion may be required. This can be achieved by placement of a VP shunt or without implanted devices via endoscopic third ventriculostomy (43).

Ancillary/Specialized Equipment

• Intervention in the angiography suite: Endovascular embolization is achieved in the angiography suite. Biplane angiography, guide catheters, guidewires, microcatheters, microguidewires, and embolic agents (coils and/or liquid embolic agents) may be required (75).
• Ultrasound guidance: Ultrasound may assist in achieving femoral artery access.