title: Single and tandem stents in sheep iliac arteries: is there a difference in patency?
abstract: OBJECTIVE
  To compare patency and neointima formation of single and tandem arterial stents.
  
  
  METHODS
  In each of six sheep, two Memotherm nitinol stents (tandem stents) were inserted into the external iliac artery on one side and a single stent into the artery on the opposite side. The size of the iliac lumen was assessed in the proximal, middle, and distal segments of the stents by intravascular ultrasound (IVUS) before, immediately after, and 1 month after implantation when the sheep were killed. Neointimal thickness was determined in the proximal, middle, and distal segments of each stent by light microscopy.
  
  
  RESULTS
  All stents remained patent. There was no significant difference in lumen and neointimal thickness between single and tandem stents. Cranial tandem stents showed a significantly wider lumen and smaller neointimal thickness than caudal tandem stents. In the proximal and distal segments, the lumen of the stents was significantly smaller and the neointimal thickness greater than in the middle segment; differences in neointimal thickness were significant only between the proximal and the middle segment.
  
  
  CONCLUSIONS
  In an experimental setting, tandem stents did not interfere with one another with regard to patency and neointima formation when compared with a single contralateral stent. Neointimal thickening after stent insertion seems to be inversely related to the original arterial diameter.
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: A
authors.initials: A
authors.lastname: Bücker
authors.forename: S
authors.initials: S
authors.lastname: Grosskortenhaus
authors.forename: R W
authors.initials: RW
authors.lastname: Günther
mesh_terms: D000792:Angiography; D017130:Angioplasty / Q000295:instrumentation* / Q000379:methods; D000818:Animals; D004195:Disease Models, Animal; D004867:Equipment Design; D004869:Equipment Safety; D007083:Iliac Artery / Q000000981:diagnostic imaging / Q000601:surgery*; D012680:Sensitivity and Specificity; D012756:Sheep; D015607:Stents; D014654:Vascular Patency / Q000502:physiology