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Arteriovenous Malformation:- What is an arteriovenous malformation (AVM)? An arteriovenous malformation (AVM) is an abnormal tangle of blood vessels that looks like a bird’s nest. The tangle is made of arteries that would normally provide blood to your brain and veins that would normally drain blood from brain tissue. Blood moves through your body within an organized closed circuit of blood vessels. Your arteries carry oxygen-rich blood from your heart to your brain and to the rest of your body’s organs and tissues. Your veins return oxygen- and nutrient-poor blood and waste products from tissues back to your heart and lungs. Normally, the exchange takes place in your capillaries, where the smallest blood vessel units of arteries and veins connect. If you have an AVM, the “bridge” of capillaries between your arteries and veins is missing. This causes high-flow arterial blood to connect directly to veins that aren’t used to high blood pressure. As a result, the abnormal connection between the artery and vein in an AVM can cause vessel rupture and bleeding into your brain. Types of AVMs The two types of AVMs are: Brain arteriovenous malformations. These develop anywhere within your brain tissue or on the surface of your brain. AVMs most commonly occur in your brain, brainstem and spinal cord. Peripheral arteriovenous malformations. These can form anywhere in your body’s 100,000 miles of blood vessels. They can happen on your face, arms or legs, and in tissues and organs like your heart, liver or lungs. How common are arteriovenous malformations? Arteriovenous malformations are rare. They’re present in about 1 in 100,000 people. Anyone can be born with an AVM. Providers mainly discover them in people from ages 20 to 40. The risk of symptoms is highest between ages 30 and 50. Symptoms and Causes What are the symptoms of arteriovenous malformations? Arteriovenous malformation symptoms may include: Seizures with or without loss of consciousness. Headache. Muscle weakness or complete paralysis. Nausea and vomiting. Numbness or tingling sensation. Dizziness. Problems with movement, speech, memory, thinking, balance or vision. Mental confusion, hallucinations or dementia. Back pain (can be sudden and severe) or weakness in your lower body (hips) and legs to your toes. Shortness of breath during exertion. Coughing up blood (if the AVM is in your lungs). Abdominal pain. Lumps on arms or legs or your trunk. Pain and swelling. You may or may not have symptoms if you have an arteriovenous malformation. Up to 15% of people with AVMs don’t have symptoms. Often, the first sign you have an AVM is after it bleeds. If you have a brain AVM and it leads to a blood vessel bleed (rupture), it can cause a stroke and brain damage. About 50% of people with a brain AVM have a brain bleed (hemorrhage) as their initial symptom. What causes an arteriovenous malformation (AVM)? Scientists aren’t sure what causes arteriovenous malformations. They believe that you’re born with them and that they likely develop during fetal development (they’re congenital). AVMs may be hereditary (run in families) in rare cases. How does an arteriovenous malformation affect my body? AVMs cause harm in the following ways: 1. Bleeding. The force of the blood flow from your arteries brings a lot of pressure to the AVM. Veins have weak walls and can’t always adjust to the pressure of blood flow. If your veins can’t handle the blood pressure, they might burst and bleed. Bleeding into surrounding tissue can cause permanent damage. Significant bleeding can result in death. 2. Pressing on body parts. An abnormal connection results in more blood in your veins. Veins can get big and press on nearby tissue. This not only prevents oxygenation, but also impacts draining through your lymphatic system. 3. Depleting tissues of needed oxygen. Because there’s no capillary bridge between arteries and veins, oxygen and nutrients don’t get to the tissue where there’s an AVM. The tissue and nerve cells at that site can die. What are the complications of arteriovenous malformations? Complications of brain AVMs include:- 1. Brain bleed/stroke. This is the biggest risk of having an AVM. A bleed from an AVM in your brain causes a stroke, brain damage or seizures. AVMs in these enclosed areas can also press on and displace parts of your brain and spinal cord. 2. Seizures. This rush of electrical activity in your brain can lead to passing out and having muscle movements you can’t control. 3. Aneurysm. This is a balloon-like bulge in the walls of any of the blood vessels feeding into or around the AVM. They develop because of weakness in your blood vessel walls. Aneurysms develop in about 50% of all brain and spinal cord AVMs. AVM-related aneurysms can increase your risk of rupture (bleeding) and bleeding-related symptoms. 4. Brain damage that affects thinking, mental processing, memory or understanding speech. 5. Coma and death, especially from a large bleed in your brain. How is an arteriovenous malformation diagnosed? Your healthcare provider will ask you about your symptoms and do a physical exam. They’ll sometimes listen for a bruit, which is a rapid blood flow sound they can hear in arteries and veins when there’s an AVM. What tests will be done to diagnose an arteriovenous malformation? Imaging tests providers use to detect arteriovenous malformations include: 1. Magnetic resonance imaging (MRI). This uses radio waves and a large magnet. 2. Computed tomography (CT) scan. This uses X-rays to create a series of images. 3. Catheter angiography. A provider inserts a tube (catheter) into an artery in your wrist or groin and moves it to an area to investigate. Dyes and X-rays help providers view details of your blood vessels. Brain imaging tests for suspected brain AVMs may include: Cerebral magnetic resonance angiography (MRA). Uses a magnetic field and radio waves to produce detailed pictures of your blood vessels in and around your brain. Computed tomography angiography (CTA). Uses X-rays to see detailed pictures of your blood vessels. Transcranial Doppler ultrasound. Uses sound waves to determine the speed of blood flow through your brain. Because many AVMs don’t cause symptoms, providers only discover some of them during an imaging test for another condition (such as injuries, vision problems or headaches) or after they bleed and cause symptoms. How is an arteriovenous malformation treated? Arteriovenous malformation treatment choices depend on: The AVM’s type, size and location, and the anatomy of your arteries and veins. Risk of AVM rupture. Your symptoms. Your age. Your general health. Ideally, the goal of arteriovenous malformation treatment is to reduce the chance of bleeding or make it permanently go away. There are several different ways to treat it. These treatment types include open surgery, catheter-based artery blocking, and/or focused radiation to the AVM. Any type of intervention has benefits and risks that depend your overall health and the characteristics of your AVM. In general, treating an arteriovenous malformation as soon as possible is usually the best way to avoid serious complications. Each person — and each person’s AVM — is unique. There aren’t any perfect decision-making tools. Your healthcare team will talk to you and your family about your situation and the best way to approach your AVM. An AVM might be in an area where the dangers of surgery or other treatments pose a greater risk than doing nothing. If this is the case, your healthcare team may carefully monitor your AVM with imaging tests over time. If the AVM begins showing signs of change, indicating an increased risk of bleeding, your provider may consider treatment at that time. Medications Medications can relieve some of the symptoms of AVMs. These include: Anti-seizure medications. Pain relievers for headache and back pain. Blood pressure medications. Procedures Healthcare providers may try one or more of these approaches: Surgery to remove the AVM. Surgery involves making a small cut near the AVM, sealing the surrounding arteries and veins so they don’t bleed, then removing the AVM. A surgeon redirects blood flow to normal blood vessels. Surgery is a cure for this condition. You’ll have a brain scan to make sure the surgery completely removed or destroyed the AVM. You’ll also have a short hospital stay (a few days) and undergo some short-term rehabilitation. Embolization. In this procedure, a provider inserts a catheter into an artery in your groin or wrist and moves it to the location of the AVM. Once there, they release a glue-like substance, coils or another substance into the AVM, which slows or stops the blood flow through the AVM. Providers use this approach when the AVMs are large and have a lot of blood flowing through them. This way, they can remove them more easily with less risk of bleeding if they perform surgery immediately afterward. Embolization can also slow blood flow to reduce rupture if a surgeon doesn’t operate immediately. Gamma Knife® radiosurgery. This approach uses highly focused beams of radiation that slowly shrink, scar and dissolve an AVM over a few years or make the AVM easier to remove with surgery. You’ll have scans from time to time to see if the AVM is shrinking. Complications of the treatment Complications or side effects from arteriovenous malformation treatment may include: Bleeding. Headache. Swelling. Damage to nearby tissues. Muscle weakness on one side. Effects on speech, hearing or vision. Results that aren’t complete, don’t last or take months to reach their full effect. Serious complications that can be disabling or fatal. Prevention Can an arteriovenous malformation be prevented? No, you can’t prevent AVMs because researchers believe they’re congenital (you’re born with them). But if you develop any of the symptoms listed in this article, see your healthcare provider right away. Responding quickly to developing symptoms is the best approach.

Key Specification Arteriovenous Malformation

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