Treatment of Arteriovenous Malformations at Interventional Neuroradiology at Alexian Brothers Neurosciences Institute

What is an arteriovenous malformations (AVM)?

An arteriovenous malformation is an abnormal collection of blood vessels (sometimes referred to as a tangle of blood vessels) that allows blood to flow directly from the arteries into the veins, and thus bypass the brain tissue. AVMs can occur in any part of the brain, and the symptoms that appear are often related to the location of the AVM. The cause of AVMs is generally unknown, but they may develop during fetal development.

AVMs can cause a variety of problems such as:

• Headaches
• Stroke, from bleeding into or around the brain
• Seizure
• Weakness, particularly on one side of the body
• Numbness, particularly on one side of the body
• Loss of vision
• Loss of speech

How are AVMs diagnosed?

We may suspect an AVM based on the findings seen on a CT scan or MRI. If an AVM is suspected, we will recommend a diagnostic cerebral angiogram to confirm the diagnosis.  Not only will an angiogram help us identify the specific vessels associated with the AVM, it will also help us plan the most beneficial therapy for you.

Treatment for AVMs

Radiosurgery

This is a non-invasive procedure that involves focusing beams of radiation on the blood vessels of the AVM. Over time, changes in the blood vessel walls lead to the development of scar tissue and obliteration of the AVM. Radiosurgery is sometimes performed in combination with embolization.

Embolization

Embolization is a minimally-invasive procedure performed by an interventional neuroradiologist to block the blood flow to the involved blood vessels. A small catheter is guided into the vessels of the brain where the AVM is present. An "embolic," glue-like material is then injected through this catheter to permanently seal off the affected blood vessels.  

In most cases, embolization will reduce the size of the AVM.  It is most commonly performed right before surgery or radiosurgery. On occasion, embolization may completely block off the AVM so that no further treatment is required.

Neurosurgery

AVMs can also be surgically removed. Often surgery is performed in addition to pre-operative embolization to achieve the best results.