title: Impacts of rapid recanalization and collateral circulation on clinical outcome after intraarterial thrombolysis.
abstract: OBJECTIVE
  Rapid recanalization might improve clinical outcomes after intraarterial thrombolysis (IAT) for acute ischemic stroke patients with collateral circulation. We determined whether rapid recanalization and collateral circulation affect clinical outcomes after IAT.
  
  
  METHODS
  We retrospectively evaluated the clinical and radiological data of 134 consecutive patients who underwent IAT for intracranial artery occlusion. The interval from symptom onset to recanalization after IAT (onset-to-recanalization time) as an estimate of the probability of good clinical outcome (modified Rankin scale 0-2) was calculated in patients with collateral circulation in the ischemic hemisphere, which was rated poor (0/1 American Society of Interventional and Therapeutic Neuroradiology criteria) or good (2-4). Changes in National Institute of Health Stroke Scale (NHISS) score before and after IAT and modified Rankins scale scores 3 months after discharge were compared with respect to onset-to-recanalization time.
  
  
  RESULTS
  In patients with good collateral circulation, the estimated onset-to-recanalization time for a 0.5 probability of a good clinical outcome was 347 minutes; with poor collateral circulation, it was 172 minutes for a 0.2 probability of good clinical outcome. Outcome analyses according to onset-to-recanalization time showed patients recanalized <6 hours had lower NHISS scores (<4.5, 4.5-6, >6 hours of onset-to-recanalization time, and non-recanalization: 5.1, 6.9, 11.9, and 19.8, respectively) at discharge and higher percentages of good clinical outcome (69%, 66.7%, 21.9%, and 0%, respectively) 3 months after IAT.
  
  
  CONCLUSIONS
  The time window to expect a high probability of a good clinical outcome after IAT is highly dependent on the collateral circulation.
authors.affiliation: Regional Cerebrovascular Center, Hospital and School of Medicine, chungnam National University, Daejeon, Korea. ; Department of Neurology, Hospital and School of Medicine, Daejeon, Korea.
authors.forename: Hye Seon
authors.initials: HS
authors.lastname: Jeong
authors.affiliation: Regional Cerebrovascular Center, Hospital and School of Medicine, chungnam National University, Daejeon, Korea. ; Department of Neurosurgery, Hospital and School of Medicine, Daejeon, Korea.
authors.forename: Hyon-Jo
authors.initials: HJ
authors.lastname: Kwon
authors.affiliation: Regional Cerebrovascular Center, Hospital and School of Medicine, chungnam National University, Daejeon, Korea. ; Department of Neurology, Hospital and School of Medicine, Daejeon, Korea.
authors.forename: Hee-Jung
authors.initials: HJ
authors.lastname: Song
authors.affiliation: Regional Cerebrovascular Center, Hospital and School of Medicine, chungnam National University, Daejeon, Korea. ; Department of Neurosurgery, Hospital and School of Medicine, Daejeon, Korea.
authors.forename: Hyeon-Song
authors.initials: HS
authors.lastname: Koh
authors.affiliation: Regional Cerebrovascular Center, Hospital and School of Medicine, chungnam National University, Daejeon, Korea. ; Department of Neurology, Hospital and School of Medicine, Daejeon, Korea.
authors.forename: Yong Soo
authors.initials: YS
authors.lastname: Kim
authors.affiliation: Regional Cerebrovascular Center, Hospital and School of Medicine, chungnam National University, Daejeon, Korea. ; Department of Neurology, Hospital and School of Medicine, Daejeon, Korea.
authors.forename: Ju Hun
authors.initials: JH
authors.lastname: Lee
authors.affiliation: Department of Information and Statistics, College of Natural Science, Chungnam National University, Daejeon, Korea.
authors.forename: Jee Eun
authors.initials: JE
authors.lastname: Shin
authors.affiliation: Department of Information and Statistics, College of Natural Science, Chungnam National University, Daejeon, Korea.
authors.forename: Suk Hoon
authors.initials: SH
authors.lastname: Lee
authors.affiliation: Regional Cerebrovascular Center, Hospital and School of Medicine, chungnam National University, Daejeon, Korea. ; Department of Neurology, Hospital and School of Medicine, Daejeon, Korea.
authors.forename: Jei
authors.initials: J
authors.lastname: Kim
keywords: Clinical outcome; Collateral circulation; Ischemic stroke; Recanalization; Thrombolysis