Arterio Venous Malformations

What is an arteriovenous malformation (AVM)?

An AVM is an abnormal tangle of blood vessels connecting arteries and veins. This disrupts the normal blood flow. Arteries take oxygen rich blood to the brain and veins carry back the oxygen-depleted blood. With an AVM the surrounding tissue may not get enough oxygen. These AVMs can rupture and result in stroke and brain damage. These AVMs are seen more commonly in brain. The cause for formation of AVM is not known.

What are the symptoms?

• Bleeding
• Progressive neurological deterioration
• Head aches
• Nausea and vomiting
• Seizures
• Loss of consciousness
• Paralysis
• Difficulty in speaking an understanding
• Memory loss and dementia
• Behavioral disturbance and learning disabilities in children

How is it diagnosed?

• Cerebral or brain angiography
• CT scan
• MRI and MR angiography

How is it treated?

Treatment depends on the size of the AVM, location of the AVM and whether it has bleed or not. AVMs which have not bled can be followed up with medications for seizures and headache. AVMs, which have bled, should be considered for treatment.

What are the modalities of treatment?

• Surgery: small AVMs located at accessible areas can be completely cured with surgery.
• Endovascular embolization: here a tube is passed into theAVM from the patient’s groin and a substance is injected to cerate an artificial clot inside the AVM. This will help in stopping the blood flow into the AVM.
• Radio surgery: where intense and highly focused beams of radiation is used to damage and occlude the AVM
• Sometimes treatment modalities are combined to get a better cure.

Authored By Dr. Sai Sudarsan