Brain Aneurysms

Also known as Berry Aneurysms (they look like berries, as in the picture above).
They are very common. It is thought between 3 - 5 % of the population have undetected brain aneurysms.
Each year the chance of an aneurysm bleeding is approximatey 1 in 1000. This is for all aneurysms but the actual risk for individual aneurysms is based on the size and location.
The size of the aneurysm is related to its bleeding risk (the larger the aneurysm, the more likely it is to bleed), and to where it is.
1/3 of patients with aneurysms have more than 1 aneurysm.
If an aneurysm bleeds, this results in Subarachnoid Haemorrhage (SAH).

Symptoms

Severe sudden onset headache (the worst headache I've ever had
Nausea and vomiting
Photophobia (you can not look at bright lights)
Drowsiness or unconsciousness
Seizures
Occasionally the shock of the bleeding it so severe that it can stop the heart. Some patients die before they reach hospital

Risk Factors

High blood pressure
Smoking cigarettes
Drugs (particularly amphetamines and cocaine)
A family history

Screening

Screening for brain aneurysms should be guided by a specialist who can explain the potential implications before imaging is performed.

Familial aneurysms are rare and a single relative with subarachnoid haaemorrhage is rarely an indicaiton.

Treatment

Brain aneurysms are treated for 2 reasons:

Unruptured Aneurysms

To prevent the risk of bleeding.

Decisions on treatment of un-ruptured aneurysms are based on the pervieved risk that they will bleed during the expected remainder of the patient's natural life, and the risks of treatment.

We currently use Ogden Tables to predict life expectancy and data from the ISUIA 2 trial to predict the anual rupture risk.

Although the ISUIA 2 data predict an 'almost zero' five year risk rupture for small aneurysms (2-7mm), it must be realized that since bleeding is rare, the 'almost zero' is a flaw of large scale population based statistics. In fact between 1/3 and 1/2 of aneurysms that bleed in the UK are 7,mm or less.

A bespoke life-time bleeding risk vs the risk of treatment can be given to patients. Ultimately it is the patient's choice as to whether they undergo treatment.

Ruptured Aneurysms

If an aneurysm has bled, there is a high chance that they will bleed again. If this happens there is a very high chance (up to 85%) that the patient will suffer a stroke or may die from the re-bleed.

Treatment modalities

Aneurysms can be treated either surgically or endovascularly. We consider which treatment can achieve the safest and most accurate repair of the blood vessel.

Surgical Treatment

Surgical treatment involves repairing the aneurysm directly through a small trap-door of bone that is temporarily removed from the skull.

The video below demonstrates dissection of the optic nerve and anterior skull base, and clipping of an aneurysm of the internal carotid artery.

Endovascular Treatment

Endovascular treatment involves navigating a wire from the groin into the arteries that supply the brain and filling the aneurysm with platinum coils that prevent blood from entering the anurysm.

This is undertaken by radiologists. If this treatment is recommended you will be spoken to by the radiologists to discuss the procedure.