Arteriovenous Malformation (AVM)

________________________________________________________________________

KEY POINTS

• An arteriovenous malformation (AVM) is a rare problem with arteries and veins that are tangled and connected abnormally. An AVM can happen anywhere in the body but usually is found in the brain or spinal area.
• Treatment depends on the location of the AVM, the size, and your child’ symptoms. Treatment may include medicines, radiation treatment, or surgery. If your child has active bleeding in the brain or spinal area, your child will need to stay in the hospital.
• Follow your healthcare provider's instructions about what symptoms to watch for and how to take care of your child at home.

________________________________________________________________________

What is an arteriovenous malformation?

An arteriovenous malformation (AVM) is a rare problem with arteries and veins that are tangled and connected abnormally. An AVM can happen anywhere in the body but usually is found in the brain or spinal area, in one spot or rarely, in more than one spot.

With normal circulation:

• The heart pumps blood to the body through the arteries.
• Arteries carry blood from the heart to the organs and limbs under high pressure.
• Veins, with the help of one-way valves, carry blood back to the heart from the organs and limbs at a lower pressure.
• Tiny webs of vessels called capillaries connect the arteries and veins.

An AVM often skips the capillaries. The arteries and veins connect directly with each other in an abnormal tangle, and blood enters the veins at high pressure. This can cause these blood vessels to leak or burst.

An AVM can be small or large, and it can get larger over time. Depending on the size and location, an AVM can be serious because it can bleed and damage the tissue around it. It can also grow large enough to put pressure on the tissue around it. The tissue is damaged when it does not get enough blood and oxygen.

If bleeding happens in the brain, it is a type of stroke. The part of the brain that loses its blood supply stops working. You may have trouble using the part of the body that is controlled by the part of the brain that is damaged.

A small amount of bleeding may cause little damage. Bigger bleeds can cause serious brain damage and sometimes death.

What is the cause?

The exact cause of an AVM is not known. It may be something that your child is born with, or it may appear later in life.

What are the symptoms?

Your child may not have symptoms of an AVM in the brain unless it bleeds. If your child does have symptoms, they may include:

• Headaches
• Seizures

Your child may have symptoms of a stroke if the AVM bleeds into the brain suddenly or if the AVM is large and reduces blood flow in the brain. Call 911 for emergency help right away if your child has symptoms of a stroke such as a change in alertness, headache, seizures, sudden vomiting, weakness, or cannot speak or move.

Symptoms of an AVM in the spinal or back area that begins to bleed suddenly may include:

• Sudden, severe back pain
• Weakness and numbness in the arms and legs

Stroke and spinal AVM are medical emergencies. Call for help right away.

How is it diagnosed?

In a child, an AVM is usually found after it bleeds into the brain. Your child’s healthcare provider will ask about your child’s symptoms and medical history and examine your child. Tests may include:

• MRA, which uses a strong magnetic field and radio waves with contrast dye to show detailed pictures of blood vessels
• MRI, which uses a strong magnetic field and radio waves to show detailed pictures of the brain and blood vessels
• Angiogram, which is a series of X-rays taken after your child’s healthcare provider injects contrast dye into the blood vessels to look for narrowing, weakness, or blockages
• Ultrasound, which uses sound waves to show pictures of the blood vessels in the neck and brain
• CT scan, which uses X-rays and a computer to show detailed pictures of the brain and blood vessels
• EEG (electroencephalogram), which uses small wires pasted or taped to your child’s head to measure and record the electrical activity of the brain to check for seizure activity

How is it treated?

Treatment depends on the location of the AVM, the size, and your child’ symptoms. It may include:

• Surgery to remove or to block the AVM
• Radiation treatment to close the blood vessels in the AVM
• Monitoring your child to watch for any change in symptoms
• Medicines to treat headaches or seizures

If your child has active bleeding in the brain or spinal area, your child will need to stay in the hospital. Your child’s treatment may include a procedure to try to stop the bleeding and fix the blood vessels causing the problem, or surgery to remove a blood clot.

How can I take care of my child?

Follow the full course of treatment prescribed by your child’s healthcare provider. Ask your provider:

• How and when you will get your child’s test results
• If there are activities your child should avoid and when your child can return to normal activities
• How to take care of your child at home. If your child had surgery or if your child had bleeding in the brain, your child may need extra care in a rehab facility or extra help at home for a while.
• What symptoms or problems you should watch for and what to do if your child has them

Make sure you know when your child should come back for a checkup. Keep all appointments for provider visits or tests.