title: Usefulness of intravascular ultrasound-guided histological measurements after stenting in porcine coronary artery.
abstract: BACKGROUND
  We evaluated the usefulness of intravascular ultrasound (IVUS) in the non-uniform distribution of in-stent neointimal hyperplasia, comparing macroscopic measurements with IVUS-guided histomorphometry.
  
  
  METHODS
  Coronary stenting was performed in 45 left coronaries of 39 pigs, using 18 Tenax (Biotronik Gmbh and Co., Berlin, Germany), 11 bare Genius (Eurocor, Bonn, Germany), 10 polymer-coated Genius (Eurocor) and six Biodivysio Matrix LO (Biodivysio Ltd, Farnham, Surrey, UK) stents. After 4 weeks, coronary angiography and IVUS with automatic pullback were performed. IVUS images were analysed using three-dimensional analysis (EchoPlaque 2; INDEC Systems Inc., Mountain View, California, USA). The stented segments were formalin fixed, embedded in Technovit 9100 and cut to 4-8 microm thick slides. The most diseased in-stent segment was 4.49 +/- 4.54 mm away from the distal stent edge assessed by IVUS. Sections of these segments were stained for histomorphometry.
  
  
  RESULTS
  A significant correlation was found between IVUS-guided histomorphometry and three-dimensional IVUS measurements of maximal intimal thickness (r = 0.6985, P < 0.005) and area (r = 0.7736, P < 0.001). Macroscopic measurements resulted in comparable maximal intimal thickness (0.83 +/- 0.43 mm compared with 0.81 +/- 0.46 mm) and area (4.44 +/- 1.73 mm2 compared with 3.45 +/- 1.55 mm2) by IVUS and histomorphometry, respectively. Although stent length, diameter, nominal inflation pressure and time and injury score did not differ between the stents, bare Genius stents resulted in significant smaller neointimal volume compared to Tenax, polymer-coated Genius and Biodivysio stents: 24.46 +/- 4.98 mm3 compared with 59.18 +/- 26.41, 60.46 +/- 10.03 and 61.41 +/- 16.27 mm3, respectively (P < 0.05).
  
  
  CONCLUSIONS
  The significant correlation between IVUS-guided histomorphometry and IVUS measurements confirms the usefulness of IVUS in evaluation of experimental in-stent restenosis. Implantation of bare Genius stents resulted in significant lower neointimal hyperplasia compared to Tenax, polymer-coated Genius or phosphorylcholine-coated Biodivysio stents.
authors.affiliation: Division of Cardiology, University of Vienna Medical Center, Austria.
authors.forename: Christoph
authors.initials: C
authors.lastname: Strehblow
authors.forename: Mariann
authors.initials: M
authors.lastname: Gyöngyösi
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Sperker
authors.forename: Maryam
authors.initials: M
authors.lastname: Shirazi
authors.forename: Ursula
authors.initials: U
authors.lastname: Windberger
authors.forename: Thea
authors.initials: T
authors.lastname: Pugatsch
authors.forename: Shmuel
authors.initials: S
authors.lastname: Ben-Sasson
authors.forename: Chaim
authors.initials: C
authors.lastname: Lotan
authors.forename: Dietmar
authors.initials: D
authors.lastname: Glogar
mesh_terms: D000818:Animals; D023903:Coronary Restenosis / Q000000981:diagnostic imaging* / Q000473:pathology*; D003331:Coronary Vessels / Q000000981:diagnostic imaging* / Q000473:pathology*; D005260:Female; D006965:Hyperplasia; D007091:Image Processing, Computer-Assisted; D021621:Imaging, Three-Dimensional; D008297:Male; D015607:Stents / Q000009:adverse effects; D013552:Swine; D018084:Ultrasonography, Interventional