What are arteriovenous malformations (AVMs)?
Arteriovenous malformations (AVMs) are defects in your vascular system. Your vascular system is your body's network of blood vessels. It includes your:
- Arteries, which carry oxygen-rich blood from your heart to your tissues and organs.
- Veins, which carry the blood and waste products back to your heart.
- Capillaries, which are tiny blood vessels that connect your small arteries to your small veins.
An AVM is an abnormal tangle of arteries and veins. They are connected to each other, with no capillaries between them. Without the capillaries, the blood flow from the arteries goes directly into the veins at a faster rate than normal. Because of this, the nearby tissue does not get all the oxygen it would normally get. This lack of oxygen can lead to tissue damage and the death of nerve cells and other cells. The fast rate of blood flow can also increase the blood pressure inside the arteries and veins. This can weaken the arteries and veins. A weakened artery or blood vessel could burst or leak blood.
What causes arteriovenous malformations (AVMs)?
AVMs are rare. The cause of AVMs is unknown. Most of the time, people are born with them. But sometimes they can appear shortly after birth or later in life.
What are the symptoms of arteriovenous malformations (AVMs)?
The symptoms of AVM will depend on where the AVM is located. They can happen anywhere in the body, but they are more common in the brain or spinal cord. Most people with brain or spinal cord AVMs have few, if any, major symptoms. But if a weakened blood vessel bursts, it can spill blood into the brain (called a hemorrhage). Severe hemorrhages can cause a stroke and brain damage.
If an AVM is causing symptoms, they can include:
- Seizures
- Headache
- Pain in the area where the AVM is located
- Vision problems
- Muscle weakness
- Problems with movement and speech
- Confusion
- Dizziness
- Loss of consciousness
How are arteriovenous malformations (AVMs) diagnosed?
To find out if you have an AVM, your health care provider:
- Will ask about your symptoms and medical history.
- Will do a physical exam. This may include listening for a bruit. A bruit is whooshing sound caused by the rapid blood flow through the arteries and veins of an AVM.
- May order imaging tests, such as a CT scan, MRI, ultrasound, or cerebral angiography. For a cerebral angiography, you are injected with a special dye that helps the blood vessels in your brain show up on x-rays.
What are the treatments for arteriovenous malformations (AVMs)?
Treatments for AVMs will depend on factors such as:
- Where the AVM is located
- Its size
- Your symptoms
- Your overall health
- Your risk of bleeding
The treatment options may include:
- Monitoring for any signs that may mean you have an increased risk of hemorrhage.
- Medicines to help with the symptoms from AVMs.
- Surgery, which may be done if you have a higher-than-usual risk of bleeding. There are a few different types of surgery for AVMs. In some cases, you may have more than one type. Surgery can be risky, especially when it's done on the brain or spinal cord. So you and your provider will need to discuss the risks and benefits of doing the surgery before you make a decision.
NIH: National Institute of Neurological Disorders and Stroke
What are vascular diseases?
Your vascular system is your body's network of blood vessels. It includes your:
- Arteries, which carry oxygen-rich blood from your heart to your tissues and organs
- Veins, which carry the blood and waste products back to your heart
- Capillaries, which are tiny blood vessels that connect your small arteries to your small veins. The walls of the capillaries are thin and leaky, to allow for an exchange of materials between your tissues and blood.
Vascular diseases are conditions which affect your vascular system. They are common and can be serious. Some types include:
- Aneurysm - a bulge or "ballooning" in the wall of an artery
- Atherosclerosis - a disease in which plaque builds up inside your arteries. Plaque is made up of fat, cholesterol, calcium, and other substances found in the blood.
- Blood clots, including deep vein thrombosis and pulmonary embolism
- Coronary artery disease and carotid artery disease, diseases that involve the narrowing or blockage of an artery. The cause is usually a buildup of plaque.
- Raynaud phenomenon - a disorder that causes the blood vessels to narrow when you are cold or feeling stressed
- Stroke - a serious condition that happens when blood flow to your brain stops.
- Varicose veins - swollen, twisted veins that you can see just under the skin
- Vasculitis - inflammation of the blood vessels
What causes vascular diseases?
The causes of vascular diseases depend on the specific disease. These causes include:
- Genetics
- Heart diseases such as high cholesterol and high blood pressure
- Infection
- Injury
- Medicines, including hormones
Sometimes the cause is unknown.
Who is at risk for vascular diseases?
The risk factors for vascular diseases can vary, depending on the specific disease. But some of the more common risk factors include:
- Age - your risk of some diseases goes up as you get older
- Conditions that can affect the heart and blood vessels, such as diabetes or high cholesterol
- Family history of vascular or heart diseases
- Infection or injury that damages your veins
- Lack of exercise
- Obesity
- Pregnancy
- Sitting or standing still for long periods of time
- Smoking
What are the symptoms of vascular diseases?
The symptoms for each disease are different.
How are vascular diseases diagnosed?
To make a diagnosis, your health care provider will do a physical exam and ask about your symptoms and medical history. You may have imaging tests and/or blood tests.
How are vascular diseases treated?
Which treatment you get depends on which vascular disease you have and how severe it is. Types of treatments for vascular diseases include:
- Lifestyle changes, such as eating a heart-healthy diet and getting more exercise
- Medicines, such as blood pressure medicines, blood thinners, cholesterol medicines, and clot-dissolving drugs. In some cases, providers use a catheter to send medicine directly to a blood vessel.
- Non-surgical procedures, such as angioplasty, stenting, and vein ablation
- Surgery
Can vascular diseases be prevented?
There are steps you can take to help prevent vascular diseases:
- Make healthy lifestyle changes, such as eating a heart-healthy diet and getting more exercise
- Don't smoke. If you are already a smoker, talk to your health care provider for help in finding the best way for you to quit.
- Keep your blood pressure and cholesterol in check
- If you have diabetes, control your blood sugar
- Try not to sit or stand for up long periods of time. If you do need to sit all day, get up and move around every hour or so. If you are traveling on a long trip, you can also wear compression stockings and regularly stretch your legs.