title: Hypertension, age, and location predict rupture of small intracranial aneurysms.
abstract: 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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Department of Neurosurgery, Yale Brain Aneurysm and AVM Center, Yale University School of Medicine, New Haven, Connecticut, USA.
authors.forename: Brian V
authors.initials: BV
authors.lastname: Nahed
authors.forename: Michael L
authors.initials: ML
authors.lastname: DiLuna
authors.forename: Thomas
authors.initials: T
authors.lastname: Morgan
authors.forename: Eylem
authors.initials: E
authors.lastname: Ocal
authors.forename: Abigail A
authors.initials: AA
authors.lastname: Hawkins
authors.forename: Koray
authors.initials: K
authors.lastname: Ozduman
authors.forename: Kristopher T
authors.initials: KT
authors.lastname: Kahle
authors.forename: Andrea
authors.initials: A
authors.lastname: Chamberlain
authors.forename: Arun P
authors.initials: AP
authors.lastname: Amar
authors.forename: Murat
authors.initials: M
authors.lastname: Gunel
mesh_terms: D000328:Adult; D000367:Age Factors; D017542:Aneurysm, Ruptured / Q000453:epidemiology* / Q000601:surgery; D005260:Female; D006801:Humans; D006973:Hypertension / Q000150:complications / Q000453:epidemiology* / Q000601:surgery; D002532:Intracranial Aneurysm / Q000453:epidemiology* / Q000601:surgery; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D012307:Risk Factors