A vein of Galen malformation (VOGM) is a brain disorder that affects the vein of Galen, one of the large veins that carries deoxygenated blood from the brain to your heart. It develops prior to birth and is diagnosed in infants and young children. VOGM is a type of arteriovenous malformation (AVM) in which the blood vessels in the brain become entangled, causing disruption of normal blood flow. VOGM is a rare disorder and is more common in males.
What Happens in a Vein of Galen Malformation?
In normal fetal development, a large vein develops at the base of the brain which eventually becomes the vein of Galen. When a child develops a vein of Galen malformation, oxygenated blood from misshapen arteries flows directly into the vein, bypassing the surrounding tiny vessels, known as capillaries. This prevents proper development of the vein of Galen and creates an excessively forceful flow of blood to the heart and lungs. The circulation of blood to the brain is hindered, leading to potentially fatal complications like pulmonary hypertension and congestive heart failure.
What Causes a Vein of Galen Malformation?
A vein of Galen malformation may occur due to a genetic abnormality. It develops in the fetus in the first trimester of pregnancy. However, it is not hereditary.
What are the Symptoms of a Vein of Galen Malformation?
The symptoms of a vein of Galen malformation differ slightly in newborns, infants and children.
Symptoms of VOGM in newborns and infants may include:
- An unusually large head, known as macrocephaly
- Prominent veins on the scalp
- “Blue baby” syndrome or cyanosis
- Fast breathing/respiratory distress
- Hydrocephalus - an accumulation of excess fluid in the brain
Symptoms in early childhood may include:
- Brain hemorrhage
- Developmental delays
- Heart failure
Diagnosis of a Vein of Galen Malformation
A vein of Galen malformation is diagnosed on a fetal ultrasound. After birth, it is diagnosed through the following tests:
Imaging tests such as computerized tomography (CT) and magnetic resonance imaging (MRI) scans, and cranial ultrasound.
Cerebral angiography, also called cerebral arteriography/angiogram: This is a minimally invasive procedure in which a catheter is inserted into a blood vessel in your groin through a tiny incision. Then, it is gently advanced towards the brain at the site of the suspected VOGM. A special dye called a contrast agent is injected into the catheter and it reaches the malformation. The flow of the contrast agent is viewed on a live X-ray, giving a detailed image of the VOGM.
Treatment of a Vein of Galen Malformation
Choice of treatment for a vein of Galen malformation depends on the severity of the condition. The treatments may include:
Non- Surgical Methods
Anti-convulsant medications may be ordered to manage seizures.
Endovascular Embolization: In this procedure, a neurosurgeon inserts a catheter through a vein or an artery in the groin and guides it up the circulatory system to the site of the vein of Galen malformation. Then a glue-like substance or metal coil is injected into the catheter, which travels to the VOGM and occludes the flow of blood to the malformed vessel that supplies the brain.
What are the Risks Associated with a Vein of Galen Malformation Surgery?
The surgical procedure may carry some risk of infection, bleeding or formation of a blood clot in the brain.
Recovery after Vein of Galen Malformation Surgery
Most children are discharged from hospital within a few days of the embolization procedure. Your doctor will give specific instructions to help you ensure a speedy recovery for your child. You will be scheduled for post-operative checkups to ensure there are no complications.