title: Determination of stent stenosis: an in vivo experimental comparison of intravascular ultrasound and angiography with histology.
abstract: OBJECTIVE
  To compare intravascular ultrasound (IVUS) and angiography with histology in determining the degree of stent stenosis in an in vivo experiment.
  
  
  METHODS
  In 16 sheep, a total of 64 stents were implanted into the external iliac arteries. Two stents were inserted on either side. Patency was followed by angiography and IVUS. Four types of stent were used: two Dacron-covered (Cragg Endopro and heparinized Cragg Endopro) and two noncovered (Cragg and Memotherm stents). Eight animals were killed after 1 month, eight others after 6 months. Histological sections were prepared from the stented vessels. Measurements of the patent and total stent diameters determined by IVUS, angiography, and histology were compared.
  
  
  RESULTS
  Correlation between IVUS and angiography was 0.75, between IVUS and histology 0.77, and between angiography and histology 0.85. A mean stent stenosis of 17 +/- 11% (range 0-51%) was found on angiography, of 10 +/- 11% (0-46%) on IVUS, and of 20 +/- 11% (4%-49%) on histology. In comparison with histology, IVUS underestimated the degree of stenosis by 10 +/- 8%, and angiography underestimated it by 3 +/- 6%. Resolution of IVUS was calculated to be about 0.35 mm and that of angiography to be about 0.15 mm.
  
  
  CONCLUSIONS
  Under experimental conditions, IVUS was not superior to angiography in determining the degree of stent stenosis in long-segment stenoses of iliac artery stents, when measurements were correlated with histology. Angiography is sufficient for following the patency of iliac artery stents.
authors.affiliation: Department of Diagnostic Radiology, University of Technology, Aachen, Germany.
authors.forename: K
authors.initials: K
authors.lastname: Schürmann
authors.forename: D
authors.initials: D
authors.lastname: Vorwerk
authors.forename: R
authors.initials: R
authors.lastname: Uppenkamp
authors.forename: B
authors.initials: B
authors.lastname: Klosterhalfen
authors.forename: A
authors.initials: A
authors.lastname: Bücker
authors.forename: R W
authors.initials: RW
authors.lastname: Günther
mesh_terms: D000792:Angiography; D000818:Animals; D003251:Constriction, Pathologic / Q000000981:diagnostic imaging* / Q000473:pathology; D005069:Evaluation Studies as Topic; D007083:Iliac Artery / Q000000981:diagnostic imaging* / Q000473:pathology; D016014:Linear Models; D012756:Sheep; D015607:Stents; D018084:Ultrasonography, Interventional; D014654:Vascular Patency