Arteriovenous malformation (AVM)

An abnormal connection or passageway between an artery and vein where the blood bypasses your capillaries. AVM's can occur anywhere in the body.

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What is AVM?

An arteriovenous malformation (AVM) is a term used to describe a complex tangle of blood vessels in your brain, where there are abnormal connections between your arteries and veins. They are almost always present at birth and arise either during very early pregnancy or as part of an inherited condition. It is believed they often occur because of a problem in blood vessel formation in the foetus during pregnancy.

An AVM can interfere with normal blood circulation, and dependent on their location can cause severe problems if they bleed. In these cases it is likely surgery will be required to remove them.

Need to know

AVM’s are often visible if they occur near the skin, as the skin will become discoloured. They will likely cause swelling and you will see blood vessels very close to the surface of the skin.

Other AVM symptoms may include:

  • Balance problems
  • Bleeding
  • Blurred vision or loss of vision
  • Confusion
  • Heart problems
  • Headache
  • Numbness and or weakness on one side of the body
  • Speech problems such as muddled words or slurred speech
  • Ulcer

It’s important to note that AVMs do not shrink over time, and so if you experience symptoms you should contact your GP or consultant as soon as possible.

In order to diagnose arteriovenous malformations, a consultant will carry out a physical examination to assess if there are any visible abnormalities present. They may also carry out the following tests to confirm a diagnosis:

They most suitable type of treatment for AVM will depend on its size, location and how restricted the blood flow is in this area, as well as if other health factors are involved. The most likely options and the reasoning for each are as follows:

  • Embolisation. This aims to block the artery supplying the arteriovenous malformation to reduce blood flow. This may be done prior to surgery with the aim of reducing bleeding during the operation or sometimes as a curative treatment in itself.
  • Gamma Knife. A type of radiation treatment, which has become the treatment of choice for many patients with arteriovenous malformations.
  • Surgery. This is to remove the arteriovenous malformation from your healthy surrounding brain tissue.

Our Arteriovenous malformation (AVM) locations

SPECIALIST UNIT  London Neurosurgery Partnership

SPECIALIST UNIT London Neurosurgery Partnership

78 Harley Street W1G 7HJ London
The Harley Street Clinic

The Harley Street Clinic

35 Weymouth Street W1G 8BJ London
The Portland Hospital

The Portland Hospital

205-209 Great Portland Street W1W 5AH London
The Lister Hospital

The Lister Hospital

Chelsea Bridge Road, SW1W 8RH London
The Shard Outpatients

The Shard Outpatients

The Shard, 32 St Thomas Street SE1 9BS London
The Cardiac Clinic

The Cardiac Clinic

London Bridge Hospital SE1 2PR London

Patient stories

This content is intended for general information only and does not replace the need for personal advice from a qualified health professional.