Aneurysms are common in the general population. It is estimated that 1 to 2% of the population harbour a brain aneurysm. The good news is that few of these aneurysms will rupture.
However, when they do rupture the consequences can be devastating. If the aneurysm ruptures it will cause a rare type of stroke, known as a subarachnoid haemorrhage. Subarachnoid haemorrhage due to an aneurysm, accounts for about 5 to 10% of all strokes.
Therefore the critical thing that your specialist will be determining is how likely it is that your aneurysm will rupture. To determine this they will ask you about risk factors such as family history, exposure to cigarette smoking, uncontrolled high blood pressure and other uncommon but related diseases.
Your specialist will then study your scans closely, looking at the location, shape and most importantly, the size of your aneurysm. In principle the larger and more irregular your aneurysm is, the higher the risk of rupture is.
There is still a variation in thought about how big is too big with regards to an aneurysm. Most practitioners would be concerned about aneurysms that were larger than 7mm, but in some cases even smaller aneurysms are a concern. This is why it is important to get a specialist opinion, to discuss your specific risk profile.
Your specialist will then decide that either your aneurysm needs to be observed, or to be treated.
If it needs to be treated, there are two possible ways that this can be done. This is determined again by individual assessment. These days more commonly the aneurysm is treated by what is known as “endovascular method”. This means that a specially trained radiologist will treat your aneurysm from inside the blood vessel. The vascular system is entered from a large blood vessel in your groin.
With special small catheters they then travel up to the blood vessels of your brain and place specific instruments like coils into the aneurysm to allow them to clot and then prevent them from bleeding. In time your body will get used to coils and the blood vessel interior will remodel to a state close to what it was before the aneurysm had formed.
The alternative method that has been practiced for an even longer time is known as clipping an aneurysm. This involves a neurosurgeon performing a brain operation that allows the blood vessels at the base of your brain to be identified and then to dissect out the aneurysm. A specially developed titanium clip is then carefully placed around the neck of the aneurysm. This means that no more blood can flow into the aneurysm, and therefore it cannot bleed again.