Small Intracranial Aneurysm Growth and Rupture Risk

Malhotra A, Wu X, Forman HP, et al.
Growth and Rupture Risk of Small Unruptured Intracranial Aneurysms: A Systematic Review. Ann Intern Med 2017;Jun 6:[Epub ahead of print].

The following are key points to remember from this review about growth and rupture risk of small unruptured intracranial aneurysms (UIAs):

  1. UIAs are increasingly being discovered, frequently incidentally from widespread imaging use.
  2. Most UIAs are small (≤7 mm in diameter) and rarely cause symptoms.
  3. Recent guidelines from the American Heart Association and American Stroke Association do not provide management recommendations for small (3-5 mm) and very small (<3 mm) aneurysms.
  4. Ten published studies highlighted both growth and rupture rates for small UIAs. These studies were observational in design. An additional 16 studies reporting either growth or rupture rate were also included in the analysis.
  5. Growth rate and rupture rate for very small and small UIAs is relatively low, but the quality of evidence is also limited due to inconsistent imaging, follow-up, and a lack of consecutive patients.
  6. Most of the studies reported annual growth rate estimates for <3% for very small (<3 mm), and small (<5 mm and <7 mm) UIAs.
  7. Most of the studies reported annual rupture rates of 0% for very small (<3 mm), <0.5% for <5 mm, and <1% for <7 mm UIAs.
  8. While these rates of growth and rupture are reassuring, it is important to note that many UIAs of this size are treated, and therefore, the growth and rupture risk is not able to be determined.
  9. All patients with UIAs should be evaluated by an expert who can weigh the risk and benefits of treatment versus watchful waiting.

Keywords: Aneurysm, Aneurysm, Ruptured, Intracranial Aneurysm, Cardiac Imaging Techniques, Cardiac Surgical Procedures, Primary Prevention, Risk, Stroke, Vascular Diseases, Watchful Waiting

< Back to Listings