The following is from Children's Hospital of Wisconsin's web site:
Arteriovenous malformation (AVM)
What is an arteriovenous malformation?
Normally, arteries carry blood with oxygen under high pressure from the heart to the brain and body.
When an arteriovenous malformation (AVM) occurs, the capillaries are missing. The arteries connect directly to the veins. This causes the blood to flow very fast through these large vessels and raises the blood pressure in the veins. Over time, this reduces the blood supply to the skin and tissue around the AVM.
What does an AVM look like?
There are some common outward signs of AVM. For example:
AVMs are most common in the head, but they may appear anywhere on the body or on internal organs.
What causes AVM?
AVM is caused by abnormal blood vessel development. Some AVMs are caused by genetic mutations and can be hereditary. . Most AVMs are present at birth (congenital), but less than half are diagnosed at birth. It may take years to be diagnosed.
How do doctors diagnose AVM?
The diagnosis is usually confirmed by an imaging test such as an ultrasound, MRI, CT or angiography. Scans must be done to see how big the malformation is and which tissues are involved. Angiography is used to precisely show which arteries are connected to which veins.
What are the complications and symptoms of AVM?
The complications and symptoms of AVM can vary from child to child, but there are some common symptoms and complications, including:
How do you treat AVM?
Treatment will vary depending on the size and location of your child’s AVM and the symptoms and complications your child is experiencing.
Treatment options may include:
Are there other problems that are linked to AVMs?
Some AVMs may be linked to a group of problems called a syndrome. Your doctor will ask you questions about the family health history. Some of the syndromes linked to AVMs are Hereditary Hemorrhagic Telangiectasia, Capillary Malformation-AVM, Bannayan-Riley-Ruvalcaba syndrome, Cowden syndrome and Parkes-Weber syndrome.
Are there other websites or references that may be helpful?
Call your child's doctor, nurse, or clinic if you have any concerns or if your child has:
Read more about arteriovenous malformations (AVM) at the Children's Hospital of Wisconsin's web site.