title: Comparison of thin-strut cobalt-chromium stents and stainless steel stents in a porcine model of neointimal hyperplasia.
abstract: BACKGROUND
  The high radial force and durability of cobalt-chromium alloy enable the construction of low-profile stents with thin struts, which improves their elasticity and may play a key role in reducing the incidence of neointimal hyperplasia as well as allow faster endothelialization. The aim of this study was to compare cobalt-chromium (CoCr) and stainless steel (SS) coronary stents in a pig model of neointimal hyperplasia.
  
  
  METHODS
  Eighteen stents were implanted into the coronary arteries of nine pigs. Control coronarography was performed 28 days after stent implantation. The animals were then sacrificed, their hearts explanted, and the coronary arteries isolated for further histopathological analysis.
  
  
  RESULTS
  Quantitative coronary angiography and histomorphometric analysis revealed no statistically significant difference between the two groups of stents. However, there was a trend toward greater late lumen loss (p=0.09) and neointimal area in the CoCr stents (p=0.08). The qualitative histopathology of the CoCr stents revealed findings typical of bare metal stents reviewed in the literature and approved for use in clinical practice. No signs of stent thrombosis, necrosis, or fibrin deposits were observed nor signs of excessive inflammatory reaction. Endothelialization was complete within 28 days.
  
  
  CONCLUSIONS
  Despite thinner struts, CoCr stents have no advantage over stainless steel stents in terms of neointimal hyperplasia inhibition. However, their positive safety results together with their high radial strength, low profile, and excellent elasticity can ensure their usage, especially in lesions of complex morphology.
authors.affiliation: Upper-Silesian Center of Cardiology, Medical University of Silesia, Katowice, Poland. kmilewski@interia.pl
authors.forename: Krzysztof
authors.initials: K
authors.lastname: Milewski
authors.forename: Aleksander
authors.initials: A
authors.lastname: Zurakowski
authors.forename: Jacek
authors.initials: J
authors.lastname: Pajak
authors.forename: Ewa
authors.initials: E
authors.lastname: Pajak-Zielinska
authors.forename: Lukasz
authors.initials: L
authors.lastname: Liszka
authors.forename: Piotr P
authors.initials: PP
authors.lastname: Buszman
authors.forename: Jaroslaw
authors.initials: J
authors.lastname: Bis
authors.forename: Marcin
authors.initials: M
authors.lastname: Debinski
authors.forename: Pawel E
authors.initials: PE
authors.lastname: Buszman
mesh_terms: D000818:Animals; D002858:Chromium Alloys; D017023:Coronary Angiography; D023903:Coronary Restenosis / Q000628:therapy*; D006965:Hyperplasia / Q000517:prevention & control*; D013193:Stainless Steel; D015607:Stents; D034421:Sus scrofa
chemical_list: D002858:Chromium Alloys; D013193:Stainless Steel