title: Impact of surgical clipping on survival in unruptured and ruptured cerebral aneurysms: a population-based study.
abstract: OBJECTIVE
  The management of aneurysms is controversial because little is known about the impact of clipping on long-term outcome. This study was designed to evaluate long-term survival of patients with aneurysms undergoing clipping in a statewide population.
  
  
  METHODS
  We used a retrospective design using an administrative database to identify patients hospitalized with aneurysms (1987 to 2001). Time-to-event analysis was used to determine the risk of death from all causes and from neurological causes.
  
  
  RESULTS
  4619 patients (mean age 54.7+/-15.3, 66.3% female) were hospitalized with cerebral aneurysms. Survival among patients with ruptures was significantly lower compared with patients with unruptured aneurysm (P<0.001) with adjusted hazard ratio (HR) of death after clipping 40% higher (HR: 1.4; 95% CI: 1.2, 1.7) in patients with rupture compared with those that were unruptured. Survival estimates for unruptured patients who underwent clipping were significantly higher than among those unruptured patients who did not undergo clipping (P<0.001), with adjusted HR of death 30% higher in patients with unruptured aneurysm that were not clipped compared with unruptured patients who were clipped (HR: 1.3; 95% CI: 1.1, 1.6). Patients with unruptured aneurysm who underwent clipping and survived beyond the 30-day postoperative period were less likely to die from neurologically related causes (5.6 versus 2.3%, P<0.001). Patients with ruptures and aneurysms who underwent clipping have a higher rate of death compared with the general population in the long-term.
  
  
  CONCLUSIONS
  Short-term and long-term mortality after clipping of cerebral aneurysms is higher than previously reported. Patients with unruptured aneurysms who undergo clipping have improved survival compared with those who do not undergo clipping. This study supports the use of early intervention in the management of patients with unruptured aneurysms.
authors.affiliation: Department of Neurosurgery, University of Washington, Seattle, Wash 98195-6410, USA.
authors.forename: Gavin W
authors.initials: GW
authors.lastname: Britz
authors.forename: Leon
authors.initials: L
authors.lastname: Salem
authors.forename: David W
authors.initials: DW
authors.lastname: Newell
authors.forename: Joseph
authors.initials: J
authors.lastname: Eskridge
authors.forename: David R
authors.initials: DR
authors.lastname: Flum
mesh_terms: D017542:Aneurysm, Ruptured / Q000401:mortality / Q000601:surgery*; D015331:Cohort Studies; D005260:Female; D006801:Humans; D002532:Intracranial Aneurysm / Q000401:mortality / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D013525:Surgical Instruments; D015996:Survival Rate; D016896:Treatment Outcome