title: Age-related differences in unruptured intracranial aneurysms: 1-year outcomes.
abstract: OBJECTIVE
  The aim of this study was to determine age-related differences in short-term (1-year) outcomes in patients with unruptured intracranial aneurysms (UIAs).
  
  
  METHODS
  Four thousand fifty-nine patients prospectively enrolled in the International Study of Unruptured Intracranial Aneurysms were categorized into 3 groups by age at enrollment: < 50, 50-65, and > 65 years old. Outcomes assessed at 1 year included aneurysm rupture rates, combined morbidity and mortality from aneurysm procedure or hemorrhage, and all-cause mortality. Periprocedural morbidity, in-hospital morbidity, and poor neurological outcome on discharge (Rankin scale score of 3 or greater) were assessed in surgically and endovascularly treated groups. Univariate and multivariate associations of each outcome with age were tested.
  
  
  RESULTS
  The risk of aneurysmal hemorrhage did not increase significantly with age. Procedural and in-hospital morbidity and mortality increased with age in patients treated with surgery, but remained relatively constant with increasing age with endovascular treatment. Poor neurological outcome from aneurysm- or procedure-related morbidity and mortality did not differ between management groups for patients 65 years old and younger, but was significantly higher in the surgical group for patients older than 65 years: 19.0% (95% confidence interval [CI] 13.9%-24.4%), compared with 8.0% (95% CI 2.3%-13.6%) in the endovascular group and 4.2% (95% CI 2.3%-6.2%) in the observation group. All-cause mortality increased steadily with increasing age, but differed between treatment groups only in patients < 50 years of age, with the surgical group showing a survival advantage at 1 year.
  
  
  CONCLUSIONS
  Surgical treatment of UIAs appears to be safe, prevents 1-year hemorrhage, and may confer a survival benefit in patients < 50 years of age. However, surgery poses a significant risk of morbidity and death in patients > 65 years of age. Risk of endovascular treatment does not appear to increase with age. Risks and benefits of treatment in older patients should be carefully considered, and if treatment is deemed necessary for patients older than 65 years, endovascular treatment may be the best option.
authors.affiliation: Department of Neurosurgery, Carver College of Medicine, University of Iowa, Iowa City, Iowa; 
authors.forename: Kelly B
authors.initials: KB
authors.lastname: Mahaney
authors.forename: Robert D
authors.initials: RD
authors.lastname: Brown
authors.forename: Irene
authors.initials: I
authors.lastname: Meissner
authors.forename: David G
authors.initials: DG
authors.lastname: Piepgras
authors.forename: John
authors.initials: J
authors.lastname: Huston
authors.forename: Jie
authors.initials: J
authors.lastname: Zhang
authors.forename: James C
authors.initials: JC
authors.lastname: Torner
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D017542:Aneurysm, Ruptured / Q000453:epidemiology / Q000601:surgery; D015331:Cohort Studies; D057510:Endovascular Procedures; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D002532:Intracranial Aneurysm / Q000453:epidemiology / Q000401:mortality / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D019635:Neurosurgical Procedures; D011446:Prospective Studies; D012189:Retrospective Studies; D016896:Treatment Outcome
keywords: ACA = anterior cerebral artery; ACoA = anterior communicating artery; BA = basilar artery; HR = hazard ratio; ICA = internal carotid artery; ISUIA = International Study of Unruptured Intracranial Aneurysms; International Study of Unruptured Intracranial Aneurysms; MCA = middle cerebral artery; MMSE = Mini-Mental State Examination; PCA = posterior cerebral artery; PCoA = posterior communicating artery; SAH = subarachnoid hemorrhage; TICS = Telephone Interview for Cognitive Status; UIA = unruptured intracranial aneurysm; age; hemorrhage; outcome; unruptured aneurysm; vascular disorders