title: Prevalence of vertebral artery origin stenosis and occlusion in outpatient extracranial ultrasonography.
abstract: OBJECTIVE
  Vertebral artery origin stenosis prevalence. Most data on the prevalence of vertebral artery origin (VAo) disease is derived from hospital-based studies of patients with posterior circulation strokes and TIA. The prevalence of VAo disease in patients without posterior circulation symptoms or asymptomatic patients is poorly characterized. Our objective was to examine the prevalence of VAo stenosis and occlusion in consecutive patients, presenting for extracranial ultrasonography at an outpatient laboratory.
  
  
  METHODS
  We retrospectively identified 2490 consecutive extracranial duplex studies performed in an ambulatory neurovascular ultrasound laboratory. All studies were reviewed for the presence of >50% VAo stenosis, defined as a PSV > 114 cm/s, and VA occlusion. We also reviewed the prevalence of >50% carotid stenosis, defined as a PSV > 120 cm/s, in the same population, to draw comparisons with VAo stenosis prevalence.
  
  
  RESULTS
  We identified right VAo stenosis in 52/1955 (2.7%) and occlusion in 74/ 1955 (3.9%) and left-sided VAo stenosis in 45/1973 (2.5%) and occlusion in 64/1973 (3.6%). The prevalence of having any (either right or left) VAo stenosis or occlusion was 8.2% and 1.4% had bilateral VAo stenosis or occlusion. Right carotid stenosis and occlusion was found in 236/2399 (9.8%) and 53/2399 (2.2%), and left carotid stenosis and occlusion in 236/2397 (9.8%) and 45/2397 (1.9%), respectively. Any carotid disease, either right or left, was present in 18.9% and 4.7% had bilateral carotid disease.
  
  
  CONCLUSIONS
  Although less prevalent than cervical carotid disease, we found that approximately 8% of patients who reported to an ambulatory ultrasound laboratory had >50% VAo disease.
authors.affiliation: Department of Neurology, Miller School of Medicine, University of Miami.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Koch
authors.affiliation: Department of Neurology, Miller School of Medicine, University of Miami.
authors.forename: Antonio J
authors.initials: AJ
authors.lastname: Bustillo
authors.affiliation: Department of Neurology, Miller School of Medicine, University of Miami.
authors.forename: Bertha
authors.initials: B
authors.lastname: Campo
authors.affiliation: Department of Neurology, Miller School of Medicine, University of Miami.
authors.forename: Nelly
authors.initials: N
authors.lastname: Campo
authors.affiliation: Department of Neurology, Miller School of Medicine, University of Miami.
authors.forename: Iszet
authors.initials: I
authors.lastname: Campo-Bustillo
authors.affiliation: Department of Neurology, Miller School of Medicine, University of Miami.
authors.forename: Mark S
authors.initials: MS
authors.lastname: McClendon
authors.affiliation: Department of Neurology, Miller School of Medicine, University of Miami.
authors.forename: Michael
authors.initials: M
authors.lastname: Katsnelson
authors.affiliation: Department of Neurology, Miller School of Medicine, University of Miami.
authors.forename: Jose G
authors.initials: JG
authors.lastname: Romano