Common Childhood Conditions
What Does an Arteriovenous Malformation (AVM) Look Like?
Arm and hand enlargement from arteriovenous malformations.
An AVM can be visible at birth, appearing as a stain that looks like a hemangioma. The skin of the AVM feels warmer to the touch than skin in other areas. The mass is dark red.
Pulsing in the mass can be seen from the rapid shunting between arteries and veins.
What Causes an AVM and Who Gets It?
The formation and exact cause of the lesion is unknown, though it seems to develop within the first trimester of pregnancy.
AVMs can be part of the syndrome in several familial genetic disorders, such as:
AVMs are assessed by stages of severity, with stage 1 being the least developed and stage 4 being the most severe.
Will an AVM Change?
Untreated AVMs slowly progress over time. The lesions become larger, darker, warmer, more painful and pulse more.
Symptoms such as pain, swelling or bleeding may develop in early childhood, or the lesion may remain unchanged until puberty or even young adulthood.
I Think I've Seen an AVM on My Child. What Should I Do Now?
A child with a suspected AVM should see a vascular anomalies specialist. Especially during and after puberty, advanced AVMs (stages 3 and 4) may cause:
- Impaired mobility
- Tissue ischemia (a decrease in the tissue blood supply)
Because the blood flows so fast through these lesions, another cause for concern with an AVM is heart failure.
The rapid shunting of blood from arteries directly to veins can cause a hyperdynamic state. When the heart has to work harder over a long period of time to push blood through these damaged vessel beds, this can lead to signs of heart failure in these patients.
Patients with extensive AVMs (such as an entire limb or head and neck) should have a complete heart exam, including echocardiography. These patients must be followed closely for signs of heart failure.
How Will Seattle Children's Diagnose an AVM?
Tools used to diagnose include:
Doppler ultrasound study
to detect abnormal shunting of arterial blood flow. If the results (called a sonogram) are suspect for AVM, an MRI or magnetic resonance angiography (MRA) will be performed.
MRI or MRA
to confirm the diagnosis, determine the extent of the AVM, and assist with planning the stages of treatment.
to provide a precise mapping of the blood vessels, both normal and abnormal, in the area of concern.
How Will Seattle Children's Treat an AVM?
We address your child's individual needs around issues such as pain, impaired mobility and bleeding to create a plan that will maximize function and quality of life.
Treatment options for AVM include removal of lesions through surgery and serial embolization procedures.
With any treatment, the team will carefully consider all options and discuss them with you. Compression garments generally do not alleviate AVM symptoms.