Understanding Arteriovenous Malformations and How They Are Treated
Understanding Arteriovenous Malformations and How They Are Treated
Arteriovenous Malformations (AVMs), most people hear this word only when they or their loved ones get diagnosed with this. Arteriovenous malformations are rare but serious abnormalities in the blood vessels. While the name may sound complicated, let’s understand this in a simpler and easier-to-understand way.
What exactly is an AVM?
Normally, in a healthy circulatory system, blood travels from the heart through arteries, passes through tiny blood vessels called capillaries, and then flows back to the heart through veins. Those capillaries play an important role in slowing down the blood flow and allowing oxygen to pass into your tissue.
An arteriovenous malformation is a tangle of blood vessels where arteries and veins connect directly without the tiny blood vessels, capillaries, in between. Instead, arteries connect directly to veins. This abnormal connection disrupts normal blood flow and circulation. Over time, this can put significant stress on the surrounding blood vessels and increase the risk of complications.
AVMs can form almost anywhere in the body, but they’re most commonly found in the brain and spinal cord. Brain AVMs are often considered more serious because they can affect critical neurological functions.
What Causes Arteriovenous Malformations?
Researchers still don’t fully understand the exact cause of AVMs. In most cases, AVMs are believed to be present from birth. It seems to be a random glitch in how blood vessels develop early on.
However, many people may live for years without knowing they have one because symptoms do not always appear immediately.
Symptoms of AVM
This is the part where things get a little complicated̤̤. In most casȩs, AVMs do not cause any symptoms at all̤. In many cases, an AVM is discovered accidentally during imaging scans done for unrelated reasons. When symptoms do appea̧r, they announce themselves like this
- Sudden onset headache and loss of consciousness,
- Seizures.
- Dizziness.
- Weakness, or numbness of one side of body.
- Difficulty in speaking or vision problems.
- Diffuculty in walking.
- Incontinence of urine.
A major concern with brain and spine AVM is internal bleeding̤ Because of the abnormal pressure within the blood vessels, there is a risk of rupture, which can cause internal bleeding or haemorrhage in the brain or in spinal cord. And it’s often how people discover they had one in the first place. This is a dangerous condition as it can lead to stroke-like symptoms or even life-threatening complications.
How Are AVMs Diagnosed?
AVMs are usually diagnosed through advanced imaging techniques. As mentioned, most AVM cases are picked up while doing the MRI or CT scan for an unrelated reason or after a bleed or seizure prompts further investigation. Common AVM diagnostic tests include MRI, CT scan, cerebral angiography, ultrasound, Diagnostic Substraction Angiography( DSA). These imaging tools help specialists determine the location, size, and severity of AVMs and also decide on the best treatment approach.
How Are Arteriovenous Malformations Treated?
The treatment for AVMs depends on several factors, including the size, location, symptoms, and risk of bleeding. Not every AVM requires immediate intervention. In some cases, doctors may recommend monitoring if the AVM is small and not causing symptoms.
However, if treatment is needed, the main goal is to prevent bleeding, reduce complications and completely cure the AVM. Some of the treatment options are as these.
1. Surgical removal
Surgery for AVMs is only recomended when that are in accessible parts of the brain and can be removed safely. During procedure, the neurosurgeon removes the tangled vessels connection entirely. This treatment can offer a defenitive cure, especially when the AVM is small and are located in areas that are easy to access.
2. Endovascular Embolization
This is a minimally invasive procedure used to block abnormal blood flow to the AVM. It involves the insertion of thin catheter through the blood vessel, usually from the groin and guiding it towards the region where AVM exists. Once it reaches the abnormal region, a special glue like material or coil is used to block the abnormal vessel.
Embolization is used on its own, as a stand alone treatment or before the surgery or radition to shrink the AVM and reduce the risk of bleeding during the surgery.
3. Stereotactic radiosurgery
This treatment uses highly focused radiation beams that are precisely aimed at the AVMs. Over time, the radiation gradually causes the blood vessel to scar and close off. The results of this treatment are gradual and takes usually two years. It is also a non-invasive procedure and often used for
a)Smaller AVMs that are non amenable for surgery/ embolisation.
b)AVM’s which could be partially treated either by embolisation or surgery.
Recovery and Long-Term Outlook
Recovery depends on the type of treatment and the severity of the condition. Some patients recover quickly after minimally invasive procedures, while others may require longer rehabilitation, especially if complications like bleeding have occurred.
Regular follow-up scans are often necessary to ensure the AVM has been fully treated and to monitor for recurrence.
Bottom line
Being diagnosed with an arteriovenous malformation can feel overwhelming but with modern medical advancements, many AVMs can be treated successfully. We have the examples where many people go on to live full and healthy life after treatment. The most important step here is early detection through regular check-ups and prompt attention to unusual neurological symptoms. This can significantly reduce the risk of serious complications.
Authored by Dr. Safal Sachidananda Shetty, an Interventional Neurologist & Stroke Expert in Bangalore with extensive clinical experience in stroke intervention, brain aneurysms, and complex neurovascular disorders. His mission is to educate, prevent, and provide advanced neurologic care using the latest medical innovations and minimally invasive procedures.