title: The role of common carotid artery end-diastolic velocity in near total or total internal carotid artery occlusion.
abstract: OBJECTIVE
  To evaluate the role of the end-diastolic velocity (EDV) in the common carotid artery (CCA) as a marker of internal carotid artery (ICA) occlusion.
  
  
  METHODS
  Validation of retrospective data in a prospective clinical study.
  
  
  METHODS
  The EDV in 94 patients with total ICA occlusion and in 24 patients with high grade (95-99%) unilateral ICA stenosis identified on extracranial carotid colour-flow Duplex imaging (CFDI) and arteriography was reviewed, and was retrospectively compared to the EDV of 176 normal individuals. Identification of patients with ICA occlusion was most accurate (99.3%) with an ipsilateral EDV > or = 12 cm/s and a DIFF > or = 10 cm/s (DIFF = contralateral EDV -- ipsilateral EDV). These values were then prospectively applied to all 886 patients (67 with high grade stenosis or occlusion) who underwent CFDI at our institution during 1994.
  
  
  RESULTS
  The EDV > or = 12 had a 92% sensitivity, a 99.4% negative predictive value (NPV) and a 85% specificity in distinguishing between occluded and patent ICA's. In combination with a DIFF > or = 10 was 80.4% sensitive and 97.5% specific. The positive predictive value of the EDV > or = 12 in the distinction between 95-99% ICA stenosis and ICA occlusion was 78.3%, and that of the combination was 85.4%. The EDV was rarely zero and 10% of patients with normal or minimally diseased ICA's had an EDV > or = 12 and/or a DIFF > or = 10.
  
  
  CONCLUSIONS
  The EDV < or = 12 cm/s is a sensitive marker of ICA occlusion with a high NPV and in combination with the DIFF > or = 10 cm/s, is specific. Nevertheless, EDV parameters are inaccurate in the distinction of 95-99% ICA stenosis from occlusion. Low EDV can be found in a number of patients with minor or no ICA disease, particularly in those with a stroke or silent cerebral infarct.
authors.affiliation: Academic Vascular Surgery Unit, St. Mary's Hospital Medical School, Imperial College of Science Technology and Medicine, London, UK.
authors.forename: A E
authors.initials: AE
authors.lastname: Androulakis
authors.forename: N
authors.initials: N
authors.lastname: Labropoulos
authors.forename: R
authors.initials: R
authors.lastname: Allan
authors.forename: T K
authors.initials: TK
authors.lastname: Tyllis
authors.forename: A
authors.initials: A
authors.lastname: al-Kutoubi
authors.forename: A N
authors.initials: AN
authors.lastname: Nicolaides
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015901:Angiography, Digital Subtraction; D001783:Blood Flow Velocity; D017536:Carotid Artery, Common / Q000000981:diagnostic imaging / Q000503:physiopathology*; D002343:Carotid Artery, Internal / Q000000981:diagnostic imaging; D016893:Carotid Stenosis / Q000000981:diagnostic imaging / Q000503:physiopathology*; D003971:Diastole; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012189:Retrospective Studies; D018615:Ultrasonography, Doppler, Color / Q000295:instrumentation / Q000379:methods / Q000706:statistics & numerical data