A developmental venous anomaly (DVA) is an arrangement of small blood vessels that may look like the spokes of a wheel that drain into a larger central vein.

DVAs also may be referred to as venous angiomas. Some doctors refer to them as caput medusae, a Latin term that means head of Medusa because the clump resembles snakes on the head of the Greek mythological character named Medusa.

Facts about developmental venous anomalies

DVAs are thought to be the most common malformation of blood vessels. They are generally considered to be benign (harmless). Rather than malformations, they are sometimes referred to as benign variations in venous drainage. By some estimates, as many as one in 50 people has at least one DVA.

DVAs generally do not cause symptoms. Many people do not know that they have one. These unusual vein formations can occur anywhere in the body but are found most often in the brain or spinal cord.

Some experts believe that DVAs contribute to other malformations, such as cerebral cavernous malformations or arteriovenous malformations, that may have more serious consequences. These consequences include bleeding in the brain and a risk for stroke.


DVAs have no symptoms. Because of this, DVAs may only be found when a doctor has ordered imaging tests to look for the cause of other health problems. Some people may never know they have a DVA, and it will only be found after their death, if an autopsy is performed.

When to call the doctor

Although serious symptoms are unlikely to occur because of a DVA, there may be related conditions, such as arteriovenous malformations or cerebral cavernomas, that can cause serious symptoms.

The greatest concern is hemorrhagic stroke, a stroke caused by bleeding from a blood vessel in the brain. Although the risk of this is very low with a DVA, paying attention to symptoms is important. If you notice symptoms, such as a seizure, numbness, vomiting, changes in vision or hearing, or physical weakness, go immediately to the emergency room or call 911 to get help.


Doctors typically take a medical history and do a physical exam. The final diagnosis is usually made based on imaging tests that show areas of blood flow. Imaging tests may include MRI or MRA, conventional angiogram, or specific types of CT scans. 


Generally, DVAs do not require treatment. Medication to treat any symptoms may be an option. These veins do a necessary job of getting blood in and out of the brain, so they do not need to be surgically removed or closed.


There is currently no way to prevent developmental venous anomalies.