What is an Arteriovenous Malformation? 

Arteriovenous malformation (AVM) is a type of vascular anomaly that results when there is an abnormal, or tangled, connection between an artery and a vein. AVMs are mainly seen in the brain and spinal cord but can also be found in other parts of the body, including the skin.

Currently, there are no known causes for AVMs, and they are more common in males. It is believed the malformations form during embryonic or fetal development. Nothing a pregnant mother does is known to cause or prevent an AVM formation.

Signs & Symptoms of AVMs

Skin appears:

  • Bluish in infancy and childhood
  • Darker red or purple as the child ages and a firm mass develops beneath the skin

Additionally, pulsing of the blood can be felt when you touch the lesion.

AVMs may not cause any symptoms unless a leak or rupture occurs. However, some symptoms associated with AVMs may be experienced, such as:

  • Headaches
  • Seizures
  • A whooshing sound (called a bruit) heard noticeably or during examination of skull with a stethoscope

If bleeding into the brain occurs, signs and symptoms are similar to those of a stroke and may include:

  • Weakness, numbness or paralysis in part of the body
  • Sudden, severe headache
  • Unsteadiness or dizziness
  • Loss of vision and/or control of eye movement
  • Difficulty speaking
  • Inability to understand others speaking

Symptoms of AVMs may appear at any age, but these vascular malformations tend to remain stable and asymptomatic until around the age of 50. In women, pregnancy may start or worsen symptoms of an AVM due to the increased blood flow and blood volume during pregnancy.


One or more of the following imaging tests may be used to diagnose an arteriovenous malformation:

  • Ultrasonography
  • Magnetic resonance imaging (MRI)
  • Magnetic resonance angiography (MRA)


Treatment approaches for arteriovenous malformations differ depending on the area of the body that is involved and can include:

  • Medication to alleviate general symptoms: This can be helpful for those who are unable to have surgery.
  • Embolization: The injection of a material into the center of the lesion is done to block the blood supply of the lesion.
  • Surgical AVM removal: A pre-operative embolization may be used to reduce blood loss.
  • Radiosurgery: This is a less invasive treatment that uses proton-beam irradiation

Why Choose Us?

The vascular anomalies program at Comer Children's offers an integrated and comprehensive approach to the diagnosis, care and management of vascular malformations. Our multidisciplinary team of pediatric experts works together to educate families and to evaluate and treat children with all types of these vascular lesions.

Resources & Support for Patients with Vascular Anomalies

Patient Resources at Comer Children’s

Kids want to feel like kids, even when they're sick. Our Child Life therapists use play, art and other approaches to take some of the scare away from the hospital experience and to help kids feel as normal as possible, in spite of their disease. Located near Comer Children's, the Ronald McDonald House provides a home away from home for families while their child is hospitalized.

Patient Resources & Support Groups

These organizations and support groups may be helpful to families and patients by providing support, education and treatment information on vascular anomalies.