What is Arteriovenous Malformation?

Alternatively known as AVM, arteriovenous malformation is a condition involving a tangle of abnormally connecting arteries and veins. It may occur in the brain, brainstem or spinal cord.

The cause of arteriovenous malformation is not known. Many appear to be congenital, but symptoms may not become apparent for many years. Trauma is also a possible cause of an AVM.

What are some Symptoms of AVM?

The most common symptom of an AVM is headaches. Other symptoms include hemorrhaging (bleeding), seizures and neurological problems such as paralysis, muscle weakness or loss of speech, vision, coordination or memory.

Only about 12% of people with AVMs have symptoms; most people with AVMs do not require treatment. Symptoms are most often noticed in a person’s twenties, thirties or forties.

How is an AVM Treated?

AVMs can be diagnosed with an angiogram in which a thin, flexible tube is inserted into an artery and guided to the AVM. A contrast dye is then introduced, revealing the AVM on x-ray. Sometimes computed tomography (CT or CAT scan) or magnetic resonance imaging (MRI) is used for diagnosis.

  • Many non-ruptured, asymptomatic AVMs can be observed and followed.
  • Conventional surgery involves entering the brain or spinal cord and removing the central part of the AVM. Minimally invasive state-of-the-art techniques are also available, particularly for AVMs deep inside the brain.
  • Embolization through a neuroendovascular treatment involves closing off the AVM blood vessels by injecting glue into them (a process referred to as endovascular gluing) or placing coils or tiny balloons there.
  • Stereotactic radiosurgery is a scalpel-free procedure that focuses radiation on the AVM. Over a period of months, the blood vessels of the AVM then degenerate and eventually close.

The type of treatment recommended depends on the size and location of the AVM, surrounding critical structures, and the patient’s general health and well-being.