Children's Hospital Colorado

Cerebrovascular Malformations (CVM)

What are cerebrovascular malformations?

Cerebrovascular malformations (CVMs) are abnormally formed blood vessels in and around the brain and spinal cord.  They may be harmless, but some cause neurological problems because of their size and location, or due to seizures or bleeding.

There are four types of CVM:

  • Arteriovenous malformations (AVMs) are tangles of abnormal blood vessels.
  • Cavernous hemangiomas (also called cavernomas and cavernous malformations) are clusters of very wide, thin-walled blood vessels.
  • Developmental venous anomalies (DVAs) are abnormally large veins.
  • Aneurysms are weak areas in the walls of arteries that balloon and bulge because of the weakness. 

What causes cerebrovascular malformations? 

No one knows for sure what causes malformations.  Most AVMs, cavernomas, and DVAs probably result from abnormal development of the blood vessels while the brain is growing.  Most aneurysms and some cavernomas probably develop after the brain is already grown.

Who gets cerebrovascular malformations? 

AVMs and DVAs can occur in anyone.

Cavernomas often run in families, especially families with Hispanic heritage; however, they also occur when no one else in the family has hada cavernoma. 

Aneurysms occur more often in adults, especially in those who smoke and have high blood pressure, but occasionally they occur in children.

Helpful resources

Children's Hospital Colorado Stroke Program

What are the signs and symptoms of cerebrovascular malformations (CVMs)?

Arteriovenous malformations (AVMs), cavernomas, and aneurysms can all cause bleeding in the brain.  This bleeding can cause symptoms such as headachesseizures, sleepiness, and neurological problems like weakness and numbness, and difficulty speaking. These problems can also occur even if a CVM causes no bleeding.

Developmental venous abnormalities (DVAs) do not usually cause symptoms or neurological problems.

What tests are used to diagnose a cerebrovascular malformation (CVM)?

If your child has symptoms of a CVM, the first step is usually a CT scan.  If the malformation has bled,it can usually be seen with a CT scan. An MRI scan is then usually ordered to get better pictures of the malformation.

Arteriovenous malformations (AVMs) and aneurysms often need a special test called an angiogram that looks specifically at blood vessels to get even more information about your child’s condition.  Sometimes, angiograms can be done in the CT or MRI scanner.  Sometimes, however, to get the best pictures, an angiogram has to be done separately in a special “angiography suite.”

What to expect in the angiography suite

First, one of our specially trained pediatric anesthesiologists will help your child go to sleep and remain sedated during the test.  Then, a doctor who specializes in angiograms in children will pass a thin, flexible tube (catheter) though an artery in the groin up to the brain, inject a dye that can be seen in x-rays into the AVM or aneurysm, and take x-rays. 

After the angiogram, the catheter will be taken out and your child will be woken up in a recovery room staffed by specially trained,“kid-friendly” nurses. Your child will stay in bed for four hours, keeping the leg used in the procedure straight and still the whole time, before getting up and going home.

Why choose Children’s Hospitals Colorado to diagnose vascular malformations?

The state-of-the art equipment at Children’s Colorado is designed to fit the various sizes of patients we treat – from infants to young adults. This helps our testing be as accurate and as comfortable as possible for your child. Plus, all of our doctors, nurses, radiologists and technicians are specially trained to perform and explain tests and procedures to your child and family.

How do our doctors diagnose CVM?

CT scans, MRI scans and angiograms all help your child’s doctor diagnose an AVM, cavernoma, or aneurysm, determine where it is in the brain, and decide how to treat it.  In the Hemorrhagic Stroke Clinic, further testing (such as genetic tests, blood tests) may be recommended to look for conditions sometimes associated with cerebrovascular malformations.

How are cerebrovascular malformations treated?

Arteriovenous malformations (AVMs) are usually operated on and surgically removed if possible. Sometimes they can be treated in the angiography suite by “embolization” (injecting glue into them after the x-ray dye to stop bleeding).  Often, AVMs are first embolized then surgically removed.  Sometimes, AVMs that can’t be cured by glue or surgery can be treated using precisely-aimed radiation, called stereotactic radiosurgery.

Aneurysms are treated by cutting off the blood flowing into them, usually by surgically applying metal clips to their outside or injecting metal coils into them. This does not harm the brain because blood flow through healthy blood vessels is not cut off.

Cavernomas are usually surgically removed if possible.  However, many cavernomas are small and don’t cause any problems or need any treatment.  They usually are followed with periodic MRI scans to make sure they’re not growing.

Why choose Children’s Hospital Colorado for your child’s cerebrovascular malformation? 

At Children’s Colorado, we treat more children with cerebrovascular malformations than all other hospitals in Colorado combined.  Our expert physicians are always able to offer the best treatment for your child’s CVM, whether it is surgery, embolization, coiling, or stereotactic radiosurgery.

In addition, some of the most advanced research on CVM is being done right here at our hospital.


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