Vascular malformations, or abnormal blood vessel changes, include venous malformations and arteriovenous malformations (AVMs). They may look like birthmarks that develop during infancy. AVMs can form in the brain or spine, causing life-threatening problems. Treatments can close the affected blood vessels.
Vascular malformations are abnormalities that involve blood vessels. These changes are typically present at birth but frequently may not become evident until later in life during childhood or even in adulthood.
Vascular malformations can develop in any part of your body — from your head to your toes. They may present as a soft tissue mass, pain, swelling and/or skin discoloration. Some vascular malformations develop on your face or neck or near your brain or spinal cord. Others look like birthmarks or red blemishes.
Rarely, vascular malformations develop during adulthood after trauma or another incident. Vascular malformations that cause pain, impair function such as vision or activities or cause bleeding or other problems may need treatment.
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Affected blood vessels may include one or more of the following structures:
Vascular malformations may appear as birthmarks on an infant’s skin. Or they may develop in practically any part of your body, including your brain or spine. Healthcare providers determine the type of vascular malformation based on the affected blood vessels.
The most common types include:
Vascular malformations and hemangiomas result from irregularities in blood vessels (vascular anomalies). They both can cause birthmark-like blemishes, but there are differences:
Most vascular malformations are slow-flow. This term means blood moves slowly through the affected blood vessels. These are venous, lymphatic or venolymphatic malformations.
AVMs are fast-flow vascular malformations. Blood moves quickly from arteries to veins, typically through a cluster of abnormal vascular channels called a nidus. This fast blood flow in large AVMs can cause your heart to work harder, increasing the risk of heart failure.
Vascular malformations are rare. They occur in about 1% of all births. The most common type, venous malformations, affects approximately 1 in every 5,000 to 10,000 people.
Most vascular malformations are a result of localized or regional abnormal development of vascular and/or lymphatic channels which develop in utero. They are typically present at birth (congenital).
Less commonly, an injury in which there’s unrecognized damage to the vessels can over time develop into a vascular malformation. An injury or hormonal changes during puberty or pregnancy can make venous malformations noticeable for the first time.
In a small number of cases, people inherit genetic changes (mutations) that make vascular malformations more likely. Researchers are still learning more about these genetic causes.
Some people inherit gene changes that cause conditions that increase the risk of vascular malformations. These conditions include:
Symptoms of vascular malformations depend on the type. Vascular malformations that affect your skin may look like a raised red, blue, purple, brown or black birthmark. These marks may swell, bleed or cause pain.
Venous malformations can cause body aches, pain, swelling, problems with blood clotting and organ damage.
Because vascular malformations don’t always cause symptoms, providers sometimes discover the condition only after ordering tests to check for a different problem.
Healthcare providers use specialized imaging tests to view blood flow and check for vascular malformations. These imaging tests include:
Treatments for vascular malformations focus on minimizing symptoms and reducing potential complications. Malformations that don’t cause problems may not need treatment and can just be observed over time.
Treatments depend on the affected blood vessels. They often involve closing off or surgically removing affected blood vessels. Most malformations can be treated using minimally invasive techniques. Providers may use:
Sometimes, your healthcare provider may recommend a biopsy to confirm the diagnosis and/or to obtain tissue for genetic testing.
Due to the complexity and rarity of vascular malformations, it’s best managed using a team approach with health care providers of multiple specialties.
Yes, vascular malformations can recur after treatment. You may need regular follow-up and testing to detect a recurrent malformation.
Vascular malformations are often present at birth (congenital). That means there isn’t a way to prevent them.
If you have a family history of a condition that causes vascular malformations, you may want to meet with a genetic counselor. This specialist can discuss options to lower the risk of passing the condition to children.
Some malformations cause no problems and can be observed. More commonly, malformations are likely to cause pain and swelling.
Some malformations interfere with exercise, sports, work or activities of daily living due to pain, or from muscle, joint or nerve involvement.
Large, high flow malformations can over time lead to heart failure.
Vascular malformations in solid organs such as your liver, kidney or uterus can lead to organ dysfunction and other complications.
Certain vascular malformations like AVMs in your brain or spine can reduce the flow of oxygenated blood to your brain. Life-threatening problems may occur, such as:
More serious malformations like AVMs in your brain can cause life-threatening problems if they begin to bleed.
The vast majority of malformations are treatable and respond well to treatment.
You may want to ask your healthcare provider the following questions:
A note from Cleveland Clinic
Vascular malformations are a rare blood vessel disorder often present at birth. Less commonly, accidents or hormone changes bring on or worsen these blood vessel changes. Healthcare providers can treat vascular malformations that look like birthmarks, although they may return. AVMs that develop in your brain or spine and cause bleeding can be life-threatening. You should talk to your healthcare provider about preventive steps if you have a genetic condition that increases the risk of vascular malformations.
Last reviewed by a Cleveland Clinic medical professional on 07/06/2022.
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