title: Predictors of clinical and angiographic outcome after surgical or endovascular therapy of very large and giant intracranial aneurysms.
abstract: BACKGROUND
  Risk factors for poor outcome in the treatment of very large (≥20-24 mm) and giant (≥25 mm) intracranial aneurysms remain incompletely defined.
  
  
  OBJECTIVE
  To present an aggregate clinical series detailing a 24-year experience with very large and giant aneurysms to identify and assess the relative importance of various patient, aneurysm, and treatment-specific characteristics associated with clinical and angiographic outcomes.
  
  
  METHODS
  The authors retrospectively identified 184 aneurysms measuring 20 mm or larger (85 very large, 99 giant) treated at Stanford University Medical Center between 1984 and 2008. Clinical data including age, presentation, and modified Rankin Scale (mRS) score were recorded, along with aneurysm size, location, and morphology. Type of treatment was noted and clinical outcome measured using the mRS score at final follow-up. Angiographic outcomes were completely occluded, occluded with residual neck, partly obliterated, or patent with modified flow.
  
  
  RESULTS
  After multivariate analysis, risk factors for poor clinical outcome included a baseline mRS score of 2 or higher (odds ratio [OR], 0.23; 95% confidence interval [CI]: 0.08-0.66; P = .01), aneurysm size of 25 mm or larger (OR, 3.32; 95% CI: 1.51-7.28; P < .01), and posterior circulation location (OR, 0.18; 95% CI: 0.07-0.43; P < .01). Risk factors for incomplete angiographic obliteration included fusiform morphology (OR, 0.25; 95% CI: 0.10-0.66; P < .01), posterior circulation location (OR, 0.33; 95% CI: 0.13-0.83; P = .02), and endovascular treatment (OR, 0.14; 95% CI: 0.06-0.32; P < .01). Patients with incompletely occluded aneurysms experienced higher rates of posttreatment subarachnoid hemorrhage and had increased mortality compared with those with completely obliterated aneurysms.
  
  
  CONCLUSIONS
  Our results suggest that patients with poor baseline functional status, giant aneurysms, and aneurysms in the posterior circulation had a significantly higher proportion of poor outcomes at final follow-up. Fusiform morphology, posterior circulation location, and endovascular treatment were risk factors for incompletely obliterated aneurysms.
authors.affiliation: Department of Neurosurgery, Stanford Stroke Center and Stanford Institute for Neuro-Innovation and Translational Neurosciences, Stanford University School of Medicine, Stanford, California 94305-5325, USA.
authors.forename: Tim E
authors.initials: TE
authors.lastname: Darsaut
authors.forename: Nicole M
authors.initials: NM
authors.lastname: Darsaut
authors.forename: Steven D
authors.initials: SD
authors.lastname: Chang
authors.forename: Gerald D
authors.initials: GD
authors.lastname: Silverberg
authors.forename: Lawrence M
authors.initials: LM
authors.lastname: Shuer
authors.forename: Lu
authors.initials: L
authors.lastname: Tian
authors.forename: Robert L
authors.initials: RL
authors.lastname: Dodd
authors.forename: Huy M
authors.initials: HM
authors.lastname: Do
authors.forename: Michael P
authors.initials: MP
authors.lastname: Marks
authors.forename: Gary K
authors.initials: GK
authors.lastname: Steinberg
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002533:Cerebral Angiography / Q000379:methods; D002648:Child; D004621:Embolization, Therapeutic / Q000009:adverse effects / Q000379:methods; D057510:Endovascular Procedures / Q000009:adverse effects / Q000379:methods; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D002532:Intracranial Aneurysm / Q000000981:diagnostic imaging* / Q000601:surgery* / Q000628:therapy; D008297:Male; D008875:Middle Aged; D019635:Neurosurgical Procedures / Q000009:adverse effects / Q000379:methods; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012189:Retrospective Studies; D016896:Treatment Outcome; D055815:Young Adult