An arteriovenous malformation (AVM) is a condition where the blood vessels in your brain or spine tangle abnormally. While some AVMs pose little or no risk to one’s health, others may be injurious when they bleed.
But the good news is that multiple treatment options are available, ranging from conventional wait and watch (observation) to surgery. Your doctor will decide the best treatment option for you, depending on the symptoms, type, and location of AVM.
What is an Arteriovenous Malformation?
Before heading towards the treatment option, let us first understand what AVM is.
The circulatory system consists of the heart and blood vessels. Three types of blood vessels make up the circulatory system: arteries, veins, and capillaries.
Typically, blood flows from the heart to the arteries, which get smaller until they turn into capillaries. Nutrients and oxygen exchange take place in the capillaries. The blood then travels from capillaries to your heart through veins.
But in AVM, arteries directly connect to veins, without capillaries in between, and form a knot of blood vessels. (Fig 1.) This creates an area of high pressure. The veins cannot take this pressure and enlarge and bulge to accept extra blood.
AVM is usually a congenital condition, meaning it is present at birth. Although AVM may develop everywhere in the body, it is commonly seen in the brain and spine, causing headaches and seizures.
Treatment for AVM
Treatment options for AVM include observation, embolization, radiosurgery, and surgery. The ideal treatment depends on the type and location of AVM, age, and physical health.
If there is no previous history of bleeding (hemorrhage), your doctor may decide to observe the condition and prescribe medicines to lower blood pressure or prevent seizure.
It is a minimally invasive procedure involving the insertion of a flexible, thin tube (catheter) through a cut in the groin to deliver obstructive materials like glue into AVM and close the abnormal connection.
The procedure time may vary for different cases, and the patient has to stay under observation in a hospital. Embolization is less invasive, reducing the risk of side-effects and promoting faster healing. It can be useful in inoperable or deep AVM.
Some disadvantages of the treatment include rebleeding and the risk of embolic stroke. Besides, multiple treatments may be needed.
It uses a highly concentrated radiation beam that focuses on the site of AVM. The radiation beam damages the blood vessels and forms a scar tissue that stops the blood flow into the AVM.
The patient can go home on the same day. Usually, the AVM blood vessels close after six months to 2 years and are replaced with scar tissue. The procedure is cut-free and painless.
Radiosurgery is ideal for smaller AVMs and may take longer to show results.
It involves creating a surgical opening in the skull through which the AVM is cut from the normal brain tissue or shrunken. Various techniques, such as electrocautery and laser, are used for the same.
The patient may need to stay in the hospital between 5 to 7 days. The primary benefit of the procedure is immediate relief from the AVM.
Side-effects include damage to the nearby brain tissue, bleeding, and stroke.
Frequently Asked Questions
1. What is an AVM?
An AVM is an abnormal knot of blood vessels, mainly present in the brain and spine.
2. What is an AVM in the brain?
An AVM in the brain is a tangle of blood vessels connecting arteries and veins in the brain.
3. What happens if the AVM ruptures in the brain?
IF the AVM ruptures in the brain, the bleeding puts pressure on the brain’s surrounding tissues and blocks the brain’s blood flow.
4. What is the AVM rupture survival rate?
The survival rate after an AVM rupture ranges from 88-33%.