Hypertension, age, and location predict rupture of small intracranial aneurysms

Neurosurgery. 2005 Oct;57(4):676-83; discussion 676-83.


Background: Although current guidelines for the management of unruptured intracranial aneurysms (IAs) suggest aneurysms larger than 7 mm should be considered for treatment, a significant number of subarachnoid hemorrhages are caused by IAs 7 mm or smaller. Thus, we sought to identify risk factors associated with the rupture of IAs 7 mm or smaller.

Methods: We identified 100 patients with subarachnoid hemorrhage resulting from IAs 7 mm or smaller between January 2001 and 2004. Patients were compared with controls (n = 51) with unruptured IAs 7 mm or smaller, diagnosed by conventional angiography or three-dimensional computerized angiography, with respect to aneurysm characteristics (size, location, and age of presentation) and risk factors (hypertension, smoking, cocaine use, and family history).

Results: Hypertensive patients with IAs 7 mm or smaller were 2.6 times more likely to experience rupture (P = 0.01; 95% confidence interval, 1.21-5.53) than patients with normal blood pressure. Posterior circulation aneurysms were 3.5 times more likely to rupture than anterior circulation aneurysms (P = 0.048; 95% confidence interval, 0.95-19.4). After adjustment for location and hypertension, the age of patient on presentation was associated with a trend toward inverse correlation with aneurysmal rupture risk (P = 0.07). Hypertension and posterior location remained significant independent predictors in the logistic regression model.

Conclusion: Among patients with small aneurysms (< or = 7 mm), hypertension, relatively young age, and posterior circulation were significant risk factors for rupture. Given the minimal long-term morbidity and mortality of treatment of unruptured aneurysms in large, tertiary medical centers, management of unruptured aneurysms 7 mm or smaller should be governed by factors other than size, specifically age, history of hypertension, and location.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Age Factors
  • Aneurysm, Ruptured / epidemiology*
  • Aneurysm, Ruptured / surgery
  • Female
  • Humans
  • Hypertension / complications
  • Hypertension / epidemiology*
  • Hypertension / surgery
  • Intracranial Aneurysm / epidemiology*
  • Intracranial Aneurysm / surgery
  • Logistic Models
  • Male
  • Middle Aged
  • Multivariate Analysis
  • Predictive Value of Tests
  • Retrospective Studies
  • Risk Factors