title: Factors affecting survival rates for acute vertebrobasilar artery occlusions treated with intra-arterial thrombolytic therapy: a meta-analytical approach.
abstract: OBJECTIVE
  To determine whether recanalization, coma at presentation, or clot location in the basilar artery influences the relative mortality risk after intra-arterial thrombolytic therapy for acute vertebrobasilar artery occlusions.
  
  
  METHODS
  Studies were identified using the MEDLINE database for January 1987 to November 1997. Series were included if they involved 10 or more patients with basilar or vertebrobasilar artery occlusions, used urokinase and/or recombinant tissue plasminogen activator, and were written in English. A fixed-effect meta-analysis approach was used to estimate the risk of death with the aforementioned risk factors. Each study was weighted according to sample size. Relative risks were calculated with 95% confidence intervals.
  
  
  RESULTS
  As calculated from peer-reviewed published data, the relative mortality risk for patients for whom recanalization was attempted but not achieved was 2.34 (95% confidence interval, 1.48-3.71; n = 126). Coma at presentation was associated with a relative mortality risk of 1.95 (95% confidence interval, 1.26-2.99; n = 145). Clot locations in the distal one-third of the basilar artery were shown to favor survival, compared with clots located in the proximal and/or middle portions of the basilar artery (relative risk, 0.52; 95% confidence interval, 0.31-0.86; n = 126).
  
  
  CONCLUSIONS
  The combined data suggest that coma at presentation has an independent and adverse effect on survival rates. Complete recanalization, distal clot location, and responsiveness at the time of presentation are statistically significant factors for increased patient survival rates.
authors.affiliation: Department of Neurosurgery, The University of Pittsburgh Medical Center, Pennsylvania 15213-2582, USA.
authors.forename: E I
authors.initials: EI
authors.lastname: Levy
authors.forename: A D
authors.initials: AD
authors.lastname: Firlik
authors.forename: S
authors.initials: S
authors.lastname: Wisniewski
authors.forename: G
authors.initials: G
authors.lastname: Rubin
authors.forename: C A
authors.initials: CA
authors.lastname: Jungreis
authors.forename: L R
authors.initials: LR
authors.lastname: Wechsler
authors.forename: H
authors.initials: H
authors.lastname: Yonas
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D003710:Demography; D005260:Female; D005343:Fibrinolytic Agents / Q000627:therapeutic use*; D006801:Humans; D007261:Infusions, Intra-Arterial; D016239:MEDLINE; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D015912:Thrombolytic Therapy / Q000379:methods*; D014715:Vertebrobasilar Insufficiency / Q000188:drug therapy* / Q000401:mortality
chemical_list: D005343:Fibrinolytic Agents