Management of Unruptured Intra-Cranial Aneurysms

The largest study determining whether those patients with aneurysms should undergo treatment is via the ISUIA (International Study of Unruptured Intra-Cranial Aneurysms)

The data implies the risk of rupture is dependent upon the site, size and also whether the patient has had a previous SAH.

In general small aneurysms <7mm in diameter and no previous SAH the risk of rupture was less than 0.1%. For aneurysms >12mm the annual risk of rupture ranged from 3-10%

As a consensus small aneurysms <7mm that are in the anterior circulation are left alone.

Like all these cases their management is discussed in the Neurovascular MDT

It is important when offering management that the following are obtained:

  1. Patients view (knowing that they have an aneurysm could cause a significant degree of anxiety
  2. Site, Size
  3. Risk of expansion (1/3 expand >3mm over 20 years)
  4. Patients demographics age, life expectancy (e.g 90 year old bed bound

For more information see ISUIA via pubmed or any journal.

Remember the risk factors for Ruptured Aneurysm include:

  1. Family History (when 2 or more 1st degree relatives have a history of cerebral aneurysms) than there is an increased risk of rupture
  2. Smoking (significantly increases the risk of rupture)
  3. Any underlying medical condition such as hypertension or a genetic pre-disposition such as PCKD and Ehrlos-Danlos syndrome


Key Points for Counselling Patients

  1. The rate of growth of cerebral aneurysm is poorly understood therefore a non-detectable small aneurysm does not mean they will be free from a SAH.
  2. For small aneurysm the risks and benefits of surgery should be discussed, like with all procedures they carry significant risks
  3. don’t forget the patient e.g a young female who wants to get pregnant because the risk of SAH increases with pregnancy, or for life insurance/mortgage
  4. Surveillance of aneurysm e.g every 3 years
  5. Conservative management  e.g stopping smoking, healthy diet, exercise, blood pressure control are all crucial
  6. Warning signs- eg. headache, neck stiffness, photophobia