title: International subarachnoid aneurysm trial (ISAT) of neurosurgical clipping versus endovascular coiling in 2143 patients with ruptured intracranial aneurysms: a randomised comparison of effects on survival, dependency, seizures, rebleeding, subgroups, and aneurysm occlusion.
abstract: BACKGROUND
  Two types of treatment are being used for patients with ruptured intracranial aneurysms: endovascular detachable-coil treatment or craniotomy and clipping. We undertook a randomised, multicentre trial to compare these treatments in patients who were suitable for either treatment because the relative safety and efficacy of these approaches had not been established. Here we present clinical outcomes 1 year after treatment.
  
  
  METHODS
  2143 patients with ruptured intracranial aneurysms, who were admitted to 42 neurosurgical centres, mainly in the UK and Europe, took part in the trial. They were randomly assigned to neurosurgical clipping (n=1070) or endovascular coiling (n=1073). The primary outcome was death or dependence at 1 year (defined by a modified Rankin scale of 3-6). Secondary outcomes included rebleeding from the treated aneurysm and risk of seizures. Long-term follow up continues. Analysis was in accordance with the randomised treatment.
  
  
  RESULTS
  We report the 1-year outcomes for 1063 of 1073 patients allocated to endovascular treatment, and 1055 of 1070 patients allocated to neurosurgical treatment. 250 (23.5%) of 1063 patients allocated to endovascular treatment were dead or dependent at 1 year, compared with 326 (30.9%) of 1055 patients allocated to neurosurgery, an absolute risk reduction of 7.4% (95% CI 3.6-11.2, p=0.0001). The early survival advantage was maintained for up to 7 years and was significant (log rank p=0.03). The risk of epilepsy was substantially lower in patients allocated to endovascular treatment, but the risk of late rebleeding was higher.
  
  
  CONCLUSIONS
  In patients with ruptured intracranial aneurysms suitable for both treatments, endovascular coiling is more likely to result in independent survival at 1 year than neurosurgical clipping; the survival benefit continues for at least 7 years. The risk of late rebleeding is low, but is more common after endovascular coiling than after neurosurgical clipping.
authors.affiliation: Neurovascular Research Unit, Nuffield Department of Surgery, University of Oxford and Oxford Radcliffe Hospitals NHS Trust, Radcliffe Infirmary, Oxford, UK. nvru@nds.ox.ac.uk
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Molyneux
authors.forename: Richard S C
authors.initials: RS
authors.lastname: Kerr
authors.forename: Ly-Mee
authors.initials: LM
authors.lastname: Yu
authors.forename: Mike
authors.initials: M
authors.lastname: Clarke
authors.forename: Mary
authors.initials: M
authors.lastname: Sneade
authors.forename: Julia A
authors.initials: JA
authors.lastname: Yarnold
authors.forename: Peter
authors.initials: P
authors.lastname: Sandercock
mesh_terms: D000203:Activities of Daily Living; D000328:Adult; D000368:Aged; D017542:Aneurysm, Ruptured / Q000401:mortality / Q000601:surgery / Q000628:therapy*; D004621:Embolization, Therapeutic / Q000009:adverse effects; D005500:Follow-Up Studies; D006801:Humans; D002532:Intracranial Aneurysm / Q000401:mortality / Q000601:surgery / Q000628:therapy*; D008875:Middle Aged; D019635:Neurosurgical Procedures / Q000009:adverse effects; D011788:Quality of Life; D012008:Recurrence; D013345:Subarachnoid Hemorrhage / Q000601:surgery / Q000628:therapy; D015996:Survival Rate; D016896:Treatment Outcome