Arteriovenous malformations (AVMs)

Arteriovenous malformations (AVMs) are congenital blood vessel abnormalities found in the brain as well as elsewhere in the body. Composed of a complex tangle of arteries and veins, AVMs wreak havoc on the normally smooth operation of the human circulatory system, with bleeding in the brain a major cause for concern. AVMs account for two percent of all strokes and require prompt medical attention.

If you or a loved one has been diagnosed with AVMs, a multi-specialty approach ensures an integrated, comprehensive treatment plan. At Edward-Elmhurst Health, neurosurgeons, neurointerventionalists and neurologists collaborate to provide a range of treatment options for AVMs, including embolization, open surgical removal and/or radiation. Many times a combination of treatments is necessary for cure.

What is an arteriovenous malformation?

In healthy individuals, the heart pumps oxygenated and nutrient-rich blood to vital organs such as the brain. Moving at relatively high speed and pressure, blood leaving the heart travels throughout the body through a series of arteries from large to small. As blood flow reaches smaller and smaller arteries, it slows its pace until eventually it has transported its precious life-sustaining cargo to the capillaries.

Among the tiniest vessels in the body, capillaries nourish brain tissue with oxygenated blood. At the same time, a carbon dioxide exchange takes place. From the capillaries, the veins carry non-oxygenated blood and other waste materials back to the heart and lungs. Blood flowing through veins, rather than via arterial routes, makes the return trip to the heart at a slower pace and with decreased pressure. It is at this point, that AVMs become a problem.

AVMs "short circuit" the system by interfering with the capillary mesh that usually exists between arteries and veins. This condition makes blood return to the veins faster and with more pressure than they are designed to handle. Without this intermediary zone of give and take, the thin walls of the veins may expand and adversely affect adjacent areas of normal brain tissue causing weakness, numbness, loss of vision or seizures. Rupture of the supplying arteries, AVM, or the enlarged veins result in bleeding.

AVMs in the brain occur in less than one percent of the U.S. population. Patients with AVMs, primarily considered to be congenital and not inherited, often are unaware of this condition until a diagnosis is made at the time of a seizure or an intracranial hemorrhage.

Symptoms of AVMs

In about half of patients with AVMs, the first symptoms are those of a stroke caused by bleeding into the brain. Symptoms of an AVM that has not bled include:

  • Seizures of all types and severity
  • Headaches
  • Confusion
  • Ear noise/buzzing
  • Problems walking
  • Blurred, decreased or double vision
  • Dizziness
  • Muscle weakness in any part of the body or face
  • Numbness in any part of the body

About 10 percent of cases in which excess bleeding (hemorrhage) is the first symptom result in death. Some patients may have permanent seizures and brain and nervous system problems. AVMs that do not cause symptoms by the time people reach their late 40s or early 50s are more likely to remain stable and rarely cause symptoms.

Diagnosis of AVMs

Edward-Elmhurst uses state-of-the-art CT (computed tomography) and MR (magnetic resonance) imaging to diagnose patients complaining of AVM symptoms such as seizure, headaches or stroke-like episodes. A cerebral angiogram or arteriogram will normally follow the confirmation of an AVM to identify the vessels creating the malformation. Following the angiogram or arteriogram, a number of factors, from patient history to AVM size and location within the brain, determine the best course of action.

Treating AVMs

At Edward-Elmhurst, our neuroscience experts provide a variety of treatments for AMVs.

Endovascular embolization

In our state-of-the-art neurointerventional lab, your neurointerventionalist will inject onyx (a glue-like substance) into the vessels of the AVM to block the abnormal vessels.

Depending on the size of the AVM, the neurointerventionalist may need to perform this procedure several times to successfully block the AVM. Once the AVM is successfully embolized, some AVMs are surgically removed or radiated to reduce size.

Following the embolization procedure, you will be transported to the Neuro Intensive Care Unit (ICU) for one to two days of close monitoring. Nurses in the Neuro ICU will perform neuro assessments, check your vital signs, and administer medications and treatments to promote your recovery.


One of our neurosurgeons will schedule an elective craniotomy for surgical removal of the embolized AVM. With the blood vessels comprising the AVM blocked, surgical removal is safer because the risk of intracranial hemorrhage is reduced.

Following craniotomy for removal of the AVM, you will be transported to the Neuro ICU for close monitoring and comprehensive care. The typical hospital length of stay is 7-12 days.

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Recovery from AVMs

Edward-Elmhurst provides integrated care from a team of neurologists, neurointerventional surgeons, neurosurgeons, skilled critical care nurses and rehabilitation therapists to help you regain strength, maximize functioning, and put you on the road to recovery.

Following treatment for an AVM, physical therapy, occupational therapy, speech therapy and swallowing therapy begin in the hospital. The goal of treatment is to help you recover as much function as possible. Recovery time is different for each person. Problems moving, thinking and talking often improve in the weeks to months after treatment.

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