For some AVMs, the risk of treatment outweighs the background risk of AVM rupture (also known as the 'Natural History' of an AVM).

For some patients, the risk of intervention might be higher than usual because of age, medical conditions, or personal preference.

And for some AVMs, there may not be a suitable treatment option.

In these cases, OBSERVATION with serial imaging will be recommended.

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What is the risk of rupture?

The risk of rupture of a brain arteriovenous malformation (AVM) varies depending on several factors, but the general annual risk of rupture is estimated to be about 2% per year. Over a lifetime, this risk accumulates, and rupture becomes a significant concern.

If an AVM has already ruptured once, the risk of a subsequent rupture increases to approximately 6% per year or higher for several years, before eventually returning to the baseline risk of about 2% per year.
 

FURTHER EXPLANATION: A 2% risk of rupture means that there is a 98% chance that an AVM won’t bleed in the next 12 months.

 

What are the possible consequences of rupture?

When a brain AVM ruptures, it causes intracranial hemorrhage, which can lead to:

• Stroke-like symptoms (weakness, numbness, or speech difficulties).

• Loss of consciousness or coma.

• Permanent neurological deficits.

• Death in severe cases.
   

The mortality rate from an AVM rupture is approximately 10-15%, and about 20-40% of survivors are left with significant long-term disabilities.

 

FURTHER EXPLANATION: About half of all patients who suffer a brain hemorrhage from an AVM will make a full recovery.

 

My AVM has been recommended for observation – what does that involve?

If the risk of treatment outweighs the risk of rupture, then some AVMs will be recommended for Observation (also referred to as ‘watch & scan’).

Although there are no medications that will reduce the risk of rupture, the following actions may help to monitor for changes in an AVM that could increase the risk of rupture:

• Monitoring and Imaging: Regular MRI and follow-up with a neurosurgeon.

• Blood Pressure Management: Keeping blood pressure under control is important.

 

📌 Important note: This information is general and should not replace advice from your treating neurosurgeon or other specialists. Always discuss your individual situation and treatment options with your specialist team.​​

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