title: Degree of carotid artery stenosis. Comparison of selective and non-selective angiographic findings with surgical specimens.
abstract: OBJECTIVE
  To compare the degree of vessel narrowing seen on selective and non-selective carotid artery catheter angiograms using criteria set by NASCET and ECST with the results obtained from corresponding surgical specimens.
  
  
  METHODS
  In 40 preoperative angiograms (20 non-selective, 20 selective) the 'distal' degree of internal carotid artery (ICA) stenosis according to NASCET criteria and the 'local' degree of stenosis according to ECST criteria was assessed. These data were compared with the 'distal' and 'local' degree of ICA stenosis obtained by measuring the specimens and the diameter of the distal ICA intraoperatively.
  
  
  RESULTS
  The median 'local' degree of stenosis was 86.5% in the specimen and 83.5% in the selective angiograms (difference not significant). In non-selective angiography the median 'local' degree of stenosis was 77.5% compared to 84% in the corresponding specimens (P < 0.01). The median 'distal' degree of stenosis in selective angiography was 76.5 versus 75.5% in the specimens (n.s.). The median 'distal' degree of non-selective angiography was 67% compared to 77.5% in the corresponding specimens (P = 0.02). The trend to underestimate high grade stenosis (above 90%) was more pronounced in non-selective than in selective angiography. Medium grade stenosis (60-80%) was slightly overestimated in selective angiography.
  
  
  CONCLUSIONS
  Selective angiography is more accurate in determining the 'true' degree of stenosis in internal carotid artery disease, taking into account a slight overestimation of medium grade stenosis. High grade stenosis is underestimated in both selective and non-selective angiography. These observations extend to both the ECST and NASCET criteria of measuring the degree of stenosis, which differ by about 10%.
authors.affiliation: Department of Radiodiagnostics, University of Heidelberg, Germany.
authors.forename: K
authors.initials: K
authors.lastname: Post
authors.forename: H H
authors.initials: HH
authors.lastname: Eckstein
authors.forename: E
authors.initials: E
authors.lastname: Hoffmann
authors.forename: S
authors.initials: S
authors.lastname: Post
authors.forename: J R
authors.initials: JR
authors.lastname: Allenberg
authors.forename: G W
authors.initials: GW
authors.lastname: Kauffmann
mesh_terms: D000368:Aged; D015901:Angiography, Digital Subtraction / Q000379:methods*; D016893:Carotid Stenosis / Q000000981:diagnostic imaging* / Q000601:surgery; D002533:Cerebral Angiography / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male