What are arteriovenous malformations (AVMs)?

Arteriovenous malformations (AVMs) are abnormal tangles of blood vessels. They cause multiple irregular connections between the arteries and veins.

Although they can develop in other parts of the body, they are most common:

  • In the brain
  • On the surface of the brain
  • In the spinal cord

Left untreated, AVMs can lead to brain and spinal cord damage because they:

  • Reduce the oxygen going to neurological tissue
  • Bleed into surrounding tissue
  • Can lead to stroke or brain damage by placing pressure on the brain or spinal cord


Many people with an AVM experience few symptoms. If they are felt, they can include:

  • Headache
  • Seizures
  • Weakness
  • Pain
  • Speech problems
  • Vision problems
  • Movement issues

Most AVMs are present at birth (congenital), but they also can appear later. 

They may be inherited, although other inherited conditions may increase the risk of having an AVM.


AVMs are most commonly discovered during treatment of unrelated disorders or at autopsy.

If one is discovered, a minimally invasive cerebral angiogram will be done to study it.

Appropriate treatment is based on the size, location, shape and blood flow to the AVM.


AVM endovascular embolization

An AVM endovascular embolization is a minimally invasive procedure that reduces or eliminates blood flow to the AVM to prevent it from rupturing. 

The procedure is performed by using a small catheter fitted with coils, glue or stents, which is then inserted into a blood vessel in the groin (the femoral artery) and threaded to the site of the AVM.

AVM resection

An AVM resection is a surgery done through the skull to remove the mass. 

This procedure involves using a microscope to very carefully and delicately separate the AVM from the surrounding tissue in the brain, cut off the blood supply, then remove it.


View All Doctors