Arteriovenous Malformations

What are Arteriovenous Malformations?

Defects in the walls of arteries, veins, and capillaries are referred to as arteriovenous malformations. An AVM is a bundle of interconnected arteries and veins without capillaries. When this setup is present, the circulation of blood and the delivery of essential nutrients throughout the rest of the body is affected.

Causes

While often occurring in the spinal cord or brain, arteriovenous malformations can occur anywhere within the body. The cause of AVMs is unknown, although there is research suggesting a link with pregnancy. AVMs frequently develop during or after pregnancy or shortly after birth.

What are the Symptoms of Arteriovenous Malformations?

Image testing, including MRIs and CT scans, are used to detect arteriovenous malformations and determine how to proceed with treatment. There are very few noticeable symptoms associated with AVMs. However, some patients who have a severe AVM may experience headaches or seizures.

Arteriovenous MalformationsĀ Causes

The cause of arteriovenous malformations (AVM) is unidentified; however, it is believed that most instances arise in fetal growth. AVM may also be formed later on in life if the central nervous system is injured.

Malformations in the veins and arteries cause AVM. Due to the malformations, the arteries and veins do not have the secondary system of capillaries and tiny blood vessels that they need. The irregular connection makes blood flow faster and it moves straight from the arteries to the veins while avoiding the nearby tissues. Quicker and more pressurized blood flow can cause hemorrhaging.

Rupture can occur if there is high blood pressure, which makes it important for those with the condition to be cautious about avoiding hypertension. Hypertension can be threatening for healthy people but is much more hazardous for those with AVM. Women who are diagnosed with AVM my experience aggravated symptoms if the variations in hormones and blood pressure cause other symptoms to emerge.

How areĀ Arteriovenous Malformations Treated?

The major concern with AVMs is the possibility of experiencing a hemorrhage (loss of blood).

Medication

Initial treatment often includes the use of medications to reduce the risk of hemorrhaging.

Radiation therapy

Focused radiation therapy using high-energy rays (X-rays) or particles may also be used to treat AVMs.

Surgery

Surgery for arteriovenous malformations is considered risky. It is only recommended when other treatments prove to be ineffective. Performed under general anesthesia, surgery is usually performed by a neurosurgeon since AVMs occur most often in the brain. During the procedure, the AVM is removed. Once removed, AVMs do not return.

Affecting about one percent of the population, arteriovenous malformations are rare. Some people are born with AVMs while others develop them later in life. There is no evidence suggesting AVMs are genetic. Treatment is often successful, with the goal being to minimize the risk of bleeding and related issues such as stroke and brain damage.

Arteriovenous MalformationsĀ Prevention

Currently, there is not a known prevention for AVM because the actual cause is unidentified. It is known that it is a congenital condition, which could point to genetic mutations in chromosome 7, but unfortunately, research is still being conducted in this area. Those with a family history of AVM should see their physician regularly for checkups; a brain scan can identify any abnormalities.

Physicians cannot always predict the state of the AVM once identified, so it is important to be consistent and cautious when monitoring in order to prevent extreme cases such as AVM rupture.

If patients with brain AVMs experience seizures or headaches, they can visit the doctor in order to get a brain scan, which can confirm the diagnosis and help prevent further damage. Further complications such as stroke, brain damage, or hemorrhaging can be prevented successfully with close monitoring.

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Last Reviewed:
September 12, 2016
Last Updated:
November 09, 2017