Aneurysm treatment

Common questions

What is an aneurysm?

An aneurysm is a bulge in the wall of a blood vessel due to a small area of weakness. As blood passes through the vessel the pressure causes outward bulging of the vessel. This can cause the aneurysm to rupture, risking severe bleeding in to the cranial cavity. Aneurysms can occur in many parts of the body but one of the most common is the brain and these are termed intracranial or cerebral aneurysms.

Brain aneurysms mostly affect adults between the ages of 40 to 60, with a higher prevalence in women. The cause of aneurysms is unknown in most cases, although some people are genetically predisposed to acquiring them. For this reason screening is recommended if somebody has two first-degree relatives with known aneurysms. Aneurysms may also develop after certain types of infections or trauma. They are extremely rare in children.

Are cerebral aneurysms dangerous?

Most aneurysms cause no symptoms and present no problems to the individual. Unfortunately the most common symptom results from sudden haemorrhage which results in a sudden severe headache (a common description is that of a “thunderclap” headache) or unconsciousness. This may be accompanied by a stiff neck, sickness and vomiting, sensitivity to light, and fainting. Aneurysm hemorrhage may result in death.

Aneurysms can also cause symptoms such as headaches, double vision, seizures, or strokes without rupturing. These effects are caused by inflammation or pressure on the surrounding brain.

I have an aneurysm. Does it need to be treated?

Whilst aneurysms can be dangerous not all need to be treated. The decision is often a complex one and requires discussion with an experienced medical professional.

If the aneurysm is causing symptoms such as double vision or headaches it may need to be treated.

If the aneurysm is not causing any symptoms it may still be recommended to treat it due to the risk of rupture. Some of the factors that make aneurysms more likely to rupture include:

  • Location: Aneurysms located in certain parts of the brain are more dangerous. This includes aneurysms within the 'posterior' circulation, which includes the basilar, vertebral, and posterior cerebral arteries. Aneurysms located outside of the dura mater (a thick protective coating surrounding the brain) pose little risk as they are unlikely to bleed in to the skull.

  • Size: Larger aneurysms are more likely to rupture. This rule does not hold universally true, however, as it is not uncommon to see ruptured smaller aneurysms.

  • Shape: Aneurysms with an irregular shape have been associated with increased rupture rates.

  • Previous aneurysm rupture: If the aneurysm has previously ruptured, or the patient has other brain aneurysms which have bled before, then treatment is more likely to be recommended.

  • High blood pressure: Blood pressure should be controlled in patients with aneurysms

  • Smoking: Aneurysms are more likely to rupture in people who smoke and cessation is recommended if possible.

  • Age: Aneurysms may pose higher risks in more elderly patients.

How are aneurysms diagnosed?

There are a few tests, each of which has its advantages and disadvantages.

  1. Computerised tomography (CT or CAT scan). This uses X-rays to image the body. It is widely accessible, quick, and is very useful to detect bleeding in or around the brain. The study can be done with or without 'contrast' dye. CT scans involve small amounts of radiation, doses which are not normally a significant risk to the patient.

  2. CT angiography (CTA). This is using a CT scan with contrast dye to visualise the blood vessels. It is non-invasive, other than a small injection for the dye. This test can visualise aneurysms accurately.

  3. Magnetic resonance imaging (MRI) and magnetic resonance angiography (MRA). This is a method of producing high resolution imaging of the body and blood vessels without the use of X-rays. Instead these scans use very strong magnets. They are slower and more expensive than CT scans, however, and cannot be be performed with patients with certain (usually older) implanted metallic devices.

  4. Cerebral angiography. This is a test using X-rays to produces very high resolution imaging and is the definitive method of identifying aneurysms (which rarely do not show up on CT or MRI scans). The patient will have a small incision in the groin or wrist and a tube is inserted in to the blood vessels of interest. Dye is then injected through the tube. More information is available about this study on this page.

How are aneurysms treated?

For some aneurysms it may be better not to treat at all. Any medical treatment involves a degree of risk, no matter how small. It is probable that for certain low-risk aneurysms the risk of treatment is outweighed by the risk the aneurysm presents. This decision is often a complex one and the wishes and needs of the patient need to be taken carefully under consideration.

For aneurysms that need treatment there are generally two main options:

  1. Endovascular treatment. This involves treating the aneurysm through the blood vessels themselves. Generally, a small incision is made in the groin or wrist and a very thin tube is directed, under X-rays, in to the aneurysm. Through this tube tiny coils can be inserted in to the aneurysm to block it off. This is less invasive than surgery, usually resulting in a lower risk of complications. It is a newer technology but has been proven in many clinical trials to be very effective.

  2. Surgical clipping. This is an operation involving temporarily removing a small amount of the skull bone ('craniotomy') to access the aneurysm. Once the aneurysm is seen a clip is placed around its neck. As the brain is very delicate this procedure is carried out with the use of an operating microscope.