Presentation of Vein of Galen Malformations in Children

Symptoms and signs

• May vary by age of presentation: Clinical presentation may vary depending on the patient’s age. Patients may present as neonates, older infants, or older children, adolescents, and adults (48).
• Signs include cranial bruits and prominent facial veins: These signs are attributable to altered hemodynamics and cerebral venous hypertension (50).

Patterns of evolution

• No stereotypic pattern of evolution: VOGM does not present with a stereotypic pattern of acquisition of signs and symptoms. However, high-output heart failure and pulmonary hypertension precede hypoxic and dyspneic signs and symptoms. Cerebral venous hypertension produces signs and symptoms of hydrocephalus, and vascular steal in the cerebral vasculature leads to developmental delay and brain atrophy.
• Risk stratification in neonates: Arko et al. described two groups of neonates with VOGM: those presenting with severe high-output heart failure in the first few days of life (neonatal at-risk group) and those presenting after the neonatal period with signs and symptoms such as macrocephaly and seizures (infantile treatment group) (51). Patients in the neonatal at-risk group require urgent embolization, whereas patients in the infantile treatment group — who are relatively stable shortly after birth — may be treated using embolization techniques several months later.

Time for evolution

• Timing and severity of clinical presentation depends on the magnitude of flow: The clinical presentation of VOGM depends on the magnitude of the flow across the shunt (39). Essentially, the higher the flow, the earlier (and potentially more severe) the presentation. The Gold et al. clinical classification system describes the typical signs and symptoms of VOGM in patients of different ages (49).
• Rapid evolution possible after transition from fetal to neonatal circulation: After delivery, neonates may experience rapid evolution of their VOGM and its sequelae due to the transition from fetal to neonatal circulation, involving loss of blood flow through the placenta, an increase in systemic vascular resistance, and closure of the ductus arteriosus (51).

Evaluation at Presentation

• History of present illness and family history: Take a comprehensive history of the patient’s symptoms and behavior prior to clinical presentation. Include a family history and the maternal and gestational history for fetal patients. The family history may be facilitated by further conversations with other family members, since some findings may be subtle or not discussed; for example, cutaneous hemangiomas may be a manifestation of a heritable vascular malformation syndrome.
• Physical examination: Physical exam may reveal signs of high-output heart failure, pulmonary hypertension, hydrocephalus, and focal neurological deficits (including cranial nerve dysfunction).
• Screening for developmental delay: Developmental delay may be assessed by parent interview or by the Denver Developmental Screening Test (52), which may have been conducted during routine well-child visits for infants and children.
• Cardiac evaluation: Adequate cardiac evaluation should be performed in children, given the high frequency of structural cardiac abnormalities (which may alter procedural sedation risk, even in the absence of high-flow heart failure). This may reveal right ventricular hypertrophy, dilation of the right heart chambers, tricuspid regurgitation, right-to-left shunting across a PDA or PFO, a dilated superior vena cava, reversal of diastolic flow in the aorta, and/or increased flow through the pulmonary artery (41,53,54). ECG may reveal right ventricular hypertrophy, right axis deviation, and/or right atrial enlargement (55,56).
• EEG: EEG may reveal seizure activity and other signs of cerebral dysfunction (24).
• Laboratory studies: Lab work can assess for renal (renal function panel), hepatic (liver enzymes and coagulation factor tests), hematologic (complete blood count), metabolic (lactic acidosis), and cardiac (BNP) abnormalities (24,57).
• Imaging: Several imaging modalities, including prenatal and cranial ultrasound, chest x-ray, computed tomography, MRI, MRA, and cerebral angiography may be used in the evaluation of VOGM (39). Some advances in prognostication depend on advanced imaging techniques that require post-acquisition processing and subspecialist expert interpretation for quantification of flow. However, surrogate measures, such as the narrowest medial-lateral width of the draining falcine sinus, may provide significant prognostic information that can guide treatment as well (51).
• Fetal imaging and prognostication: Advances in fetal imaging have increased the detection of VOGM in utero. These advances have also enabled the identification of signs of fetal injury from the shunting that may portend a low likelihood of favorable outcome; this includes hydrops fetalis but may also include more subtle findings of structural brain injury or delayed brain development (58).
• Bicêtre Neonatal Evaluation Score: Evaluation of cardiac, cerebral, respiratory, hepatic, and renal function enables calculation of the Bicêtre Neonatal Evaluation Score, valid only in neonates (24). This score is used by some to predict outcomes for a neonate with VOGM and to establish the need for immediate treatment.

Intervention at Presentation

Stabilization

Cardiovascular and respiratory stabilization of patients presenting with VOGM is crucial. This begins with early admission to the ICU (44) and formation of a team that includes pediatric cardiologists, intensivists, and other specialists (60).

• Heart failure-related protocols: Tracheal intubation and mechanical ventilation may be required for patients in severe distress due to heart failure (44). This reduces oxygen consumption (by decreasing the work of breathing) and mitigates heart failure by decreasing right ventricular preload. Noninvasive respiratory support may be indicated for patients in less severe distress (59). Continuous pulse oximetry should be utilized and the FiO2 of supplemental oxygen adjusted to maintain a goal oxygen saturation of 100% while avoiding hyperoxia (44).
• Sedation and warming: These interventions can also reduce oxygen consumption (44).
• Diuresis: Diuresis has been used to decrease right ventricular preload (59). Monitoring of potassium levels and potassium supplementation may be required, as loop diuretics lead to potassium wasting (44).
• Improving cardiac output: Cardiac output can be improved by increasing contractility and decreasing afterload (44). Inotropes such as dopamine, dobutamine, milrinone, and/or digoxin may be used to improve myocardial contractility (44,60,61). Vasodilators such as nitroprusside, glyceryl trinitrate, and milrinone can be used to decrease afterload (62).
• Pulmonary hypertension: This may be managed with inhaled nitric oxide (60,61).
• Maintenance of PDA: Infusion of alprostadil (prostaglandin E1) can be used to maintain a PDA (which improves systemic blood flow), reduce systemic vascular resistance (which decreases left ventricular afterload and increases cardiac output), and reduce pulmonary hypertension (41,61,63).
• Management of seizures: Seizures portend a poor prognosis. The subspecialist expertise of pediatric neurologists is important, given the need to monitor for subclinical seizures using EEG and actively titrate antiseizure medications in response to both (41).

Preparation for definitive intervention, nonemergent

• MRI: MRI at birth helps delineate the structure of the lesion and the supply to the VOGM.
• ECGs: These can define structural heart defects and functional metrics. The frequency of this imaging modality is determined by the patient’s clinical status (as frequently as daily to assess response to medical management, spacing to weekly or monthly if the patient is discharged from the hospital).
• Cranial ultrasound: If the patient is able to be discharged from the hospital, schedule monthly follow-up with cranial ultrasounds to identify changes in brain volume or in the ventricles.
• Repeat MRI and MRA when planning for an elective cerebral angiogram.
• Cerebral angiogram can be combined with intervention.

Preparation for definitive intervention, emergent

• Stabilization of cardiac, pulmonary, and coagulation function: This is necessary before undergoing a procedure wherein there may be additional fluid shifts. Patients may require blood pressure support and inhaled nitric oxide to address pulmonary hypertension.
• Importance of intervention: Ultimately, the cause of high-output heart failure is the VOGM itself; therefore, intervention may be necessary to reduce dependence on medical therapies.
• Prevention of further injury: The decision to pursue treatment should be informed by the degree of brain and other organ injury, as endovascular treatment tends to not reverse injury but prevent further injury.

Admission orders

Admission orders include:

• Neonatal critical care in the ICU
• Continuous oxygen saturation monitoring
• SpO2 target of 94% to 99%
• Venous access
• Fluid goal of 80 mL/kg/day
• Adequate nutrition
• Maintenance of the umbilical artery access for interventions in unstable patients