Arteriovenous malformations or arteriovenous malformations (AVM) are abnormal networks of blood vessels that connect arteries and veins. Arteriovenous malformations are generally congenital, meaning they are present at birth.
Basically, the circulatory system has three types of blood vessels, namely arteries, veins, and capillaries. Arteries act as a supply of oxygen-rich blood from the heart to the body's cells, while the veins function to return blood full of carbon dioxide from the body's cells to the heart.
Arteries and veins are connected by small and thin blood vessels called capillaries. When blood from the arteries passes through the capillaries to go to the veins, blood flow will slow down so that the process of exchanging oxygen (from blood to tissues) and carbon dioxide (from tissues to blood) runs optimally.
When an arteriovenous malformation occurs, the arteries and veins are connected directly without going through the capillaries. This condition then causes disturbances in the circulatory system in the body and has the potential to cause death.
Causes of Artery Venous Malformations
In arteriovenous malformations, the blood vessels that connect arteries and veins are large and thick, unlike capillaries. This disorder can occur in any part of the body, but is most common in the brain, neck, and spine.
It is not known exactly the process behind the formation of AVM. However, there are allegations that this condition occurs due to genetic abnormalities in the fetus due to hereditary factors. In addition, it is also suspected that vascular malformations can occur after birth (until adulthood) due to injury to the central nervous system.
Arterial vein malformations are more at risk in people who have these factors:
- Male gender
- Have a family history of arteriovenous malformations
- Have a family history of genetic disorders, such as Cobb syndrome, hereditary hemorrhagic telangiectasia , and Sturge-Weber syndrome
Arterial Venous Malformation Symptoms
The flow of blood from the arteries to the veins in an arteriovenous malformation is different from that in the capillaries. In AVM, blood flow can be too fast, so that the exchange of oxygen and carbon dioxide is not effective.
Even so, arteriovenous malformations generally do not cause any symptoms. This condition only causes symptoms if the AVM increases in size, usually due to puberty, pregnancy, or injury.
In some cases, AVM can cause the surrounding tissue to not get enough blood supply. A large AVM can also compress surrounding tissue and cause disruption.
Specifically, the symptoms of arteriovenous malformations can be divided based on the location or age of the sufferer. Here is the explanation:
Arterial venous malformations in the brain
Early symptoms that can occur are:
- Learning difficulties and behavioral disorders in children and adolescents
- Headache or migraine
- Numbness and tingling in certain parts of the body
In certain cases, arteriovenous malformations can be damaged or ruptured. These conditions can cause more serious symptoms, including:
- Nausea and vomiting
- Severe headache
- Weakness, numbness, or paralysis
- Loss of vision
- It's hard to talk
- Difficult to make plans
- Confused or difficult to interact with others
- It's hard to keep the body balance
- Lost consciousness
- Lost memory
M alformation of the arteries and veins in the spine
Commonly found symptoms are:
- Arms and legs immovable
- Muscle weakness
- Body balance disorders
Malformations of venous arteries in the organs, chest, or abdomen
Symptoms of an AVM in this location may be easier to feel and more bothersome. Symptoms that may appear include:
- Abdominal pain
- Back pain
- Chest pain
- The sound of flowing blood is heard from the malformed blood vessels
In addition, a type of arteriovenous malformation called venous Galen malformation can cause specific symptoms in newborns or under 2 years of age. These symptoms can include:
- Swelling of blood vessels in the scalp
- Failed to thrive
- Congenital heart failure
Although it can appear at any time, symptoms of arteriovenous malformation are more common at the age of 10–40 years. This condition is usually stable and does not cause symptoms when it reaches the age of 50 years.
Arterial Venous Malformation Stage
In general, the severity of arteriovenous malformations can be classified as follows:
- Stage 1: AVM has not yet caused symptoms or is only accompanied by mild symptoms, such as the skin area on the affected part feeling warm or reddish in color.
- Stage 2: The AVM enlarges and causes palpable or audible pulsations.
- Stage 3: AVM causes pain, bleeding, or sores.
- Stage 4: AVM causes heart failure due to the large amount of ineffective blood flow in the body.
When to see a doctor
Seek immediate medical attention if you experience the symptoms mentioned above, especially if you have risk factors for arteriovenous malformation. Brain bleeding due to arteriovenous malformations can be life-threatening, so it is necessary to get medical treatment as early as possible.
If your family has a history of arteriovenous malformations, consult your doctor about your and your child's risk of developing this condition. This needs to be done immediately if there are early symptoms of AVM such as migraines or headaches, difficulty concentrating or learning difficulties, or seizures for no apparent reason.
Diagnosis of arteriovenous malformations
Diagnosis of arteriovenous malformations usually begins by asking about the patient's symptoms and medical history. After that, the doctor will do a complete physical examination. If possible, the doctor will listen to the sound of blood flow in the part that has the complaint.
To confirm the diagnosis, the examination is continued by carrying out a series of tests. Tests that can be used to diagnose arteriovenous malformations include:
- Angiography , to see in detail the shape of the veins and arteries
- CT scan , to produce images of organs, such as the head, brain, and spine, and to help detect bleeding
- MRI, to produce images of the condition of organ tissues, including blood vessels, in more detail
- MRA, to find out the pattern, speed, and range of blood flow in the malformed blood vessels
Treatment of Artery Venous Malformations
Treatment of arteriovenous malformations aims to relieve the symptoms experienced, improve the patient's quality of life, and prevent bleeding. The method of treatment used will be adjusted to the location and size of the arteriovenous malformation, the patient's age, and the patient's general health.
There are several treatment methods that can be done, namely:
The doctor can give medicines to relieve the symptoms that appear. For example, analgesic-antipyretic drugs to relieve headaches, and anti-seizure drugs (such as carbamezapine or lorazepam ) to treat seizures.
Surgery is generally performed if the arteriovenous malformation is at risk for rupture. The goal of this procedure is to repair or remove damaged blood vessels.
Several surgical methods that are commonly performed by doctors to treat arteriovenous malformations are:
Endovascular embolization The
doctor will insert a catheter into the artery, then insert a special substance that functions to inhibit and reduce blood flow to the malformed arteries and veins.
Stereotactic radiosurgery This procedure uses radiation aimed precisely at the arteriovenous malformation, to damage the blood vessels. Arterial vein malformations that are damaged will slowly die after 2–3 years of treatment. Stereotactic radiosurgery is commonly used to treat small to moderate arteriovenous malformations.
AVM removal surgery This operation aims to remove arteriovenous malformations that have caused bleeding. However, this procedure can only be performed if the malformation occurs in easily accessible blood vessels. If the malformation is in a deep part of the brain, the patient is at high risk of complications. Therefore, the doctor will use another method.
After undergoing treatment with the methods above, the patient still needs to have periodic checks to the doctor. The examination includes scanning tests to ensure that the arteriovenous malformation has completely healed and has not recurred.
Routine examination will also be recommended if the arteriovenous malformation is in a part of the body that is difficult to treat, or does not cause symptoms and only requires supervision from a doctor.
Complications of Artery Venous Malformations
Complications that can occur in patients with arteriovenous malformations can vary. However, the most common complications due to arteriovenous malformations include:
- Hemorrhagic stroke or ischemic stroke
- Numbness in certain parts of the body
- Difficulty speaking or moving
- Developmental delays in children
- Hydrocephalus in babies
- Permanent brain damage
- Decreased quality of life
- Death from bleeding
Prevention of arteriovenous malformations
As explained above, the exact cause of arteriovenous malformations cannot be known. Therefore, it is not yet known how to prevent this condition from occurring. The best thing that can be done is to treat the symptoms experienced early to prevent complications, for example by:
- Take medication prescribed by a doctor
- Manage high blood pressure (if present)
- Do not take drugs or herbal products that can thin the blood without doctor's confirmation
- Undergo regular doctor check-ups