title: Nonocclusion and spontaneous recanalization rates in acute ischemic stroke: a review of cerebral angiography studies.
abstract: BACKGROUND
  Spontaneous recanalization is an understudied phenomenon in stroke. It is often overestimated by nonocclusion rates. The heterogeneity of the causes and manifestations of stroke and of the studies assessing vascular patency has created difficulties in assigning accurate rates of its incidence.
  
  
  METHODS
  Systematic review of published articles about cerebral angiography in stroke.
  
  
  RESULTS
  Lack of anticipated occlusions (nonocclusion rates) was noted in 28% of patients in suspected vessels 6 hours after stroke onset, whereas documented occlusions were noted in 17% of patients who underwent spontaneous lysis at 6 to 8 hours. At 3 to 4 days, the nonocclusion rate was 50% of studied vessels.
  
  
  CONCLUSIONS
  In the first 6 to 8 hours from stroke onset, spontaneous recanalization occurs in approximately 17% of patients, whereas nonocclusion exists in about 28% of patients and up to 50% by 4 days after stroke.
authors.affiliation: Department of Medicine, Duke University Medical Center, Durham, NC 27710, USA.
authors.forename: Hassan
authors.initials: H
authors.lastname: Kassem-Moussa
authors.forename: Carmelo
authors.initials: C
authors.lastname: Graffagnino
mesh_terms: D000208:Acute Disease; D002545:Brain Ischemia / Q000000981:diagnostic imaging*; D002533:Cerebral Angiography / Q000379:methods / Q000706:statistics & numerical data; D002986:Clinical Trials as Topic / Q000706:statistics & numerical data; D006801:Humans; D020521:Stroke / Q000000981:diagnostic imaging*; D013997:Time Factors