title: Serial intravascular ultrasonographic measurements after implantation of biodegradable polymer-coated stents in porcine coronary arteries.
abstract: BACKGROUND
  Biodegradable stent coatings provide a potential for local drug delivery at the time of vascular injury, while possible tissue toxicity is avoided through constant degradation, leaving behind a bare metal stent.
  
  
  METHODS
  Serial three-dimensional (3D) intravascular ultrasonographic results on bare Megaflex stents and biodegradable polymer-coated Megaflex stents (Hyper stents) (Eurocor, Bonn, Germany) were compared 1 and 4 weeks after intracoronary implantation in pigs.
  
  
  METHODS
  Under general anaesthesia, the left anterior descending and circumflex coronary arteries of domestic pigs were stented with Megaflex and Hyper stents, using right femoral artery access. Control coronary angiography and intravascular ultrasonography (IVUS) were performed 1 and 4 weeks after stent implantation using left femoral artery access and right carotid artery access. After recording of angiographic and IVUS data, the pigs were allowed to recover.
  
  
  RESULTS
  The 1- and 4-week IVUS follow-ups revealed less neointima formation with Hyper stents than with Megaflex stents: 1-week intimal volume, 11.8+/-0.93 compared with 15.02+/-4.18 mm3, P=0.065; intimal area, 0.81+/-0.06 compared with 1.1+/-0.16 mm2, P =0.003; maximal intimal thickness, 0.12+/-0.01 compared with 0.14+/-0.02 mm, P =0.049; 4-week intimal volume, 12.4+/-1.77 compared with 27.32+/-12.79 mm3, P =0.016; intimal area, 0.82+/-0.12 compared with 1.95+/-0.65 mm2, P=0.003; and maximal intimal thickness, 0.13+/-0.04 compared with 0.30+/-0.10 mm, P=0.003.
  
  
  CONCLUSIONS
  Implantation of biodegradable polymer-coated (Hyper) stents results in significantly less neointima formation 1 and 4 weeks after intracoronary implantation than with bare Megaflex stents. Taking advantage of the good collateralization of femoral and carotid arteries of pigs, the use of different arterial accesses allows serial angiographic and 3D IVUS measurements on neointimal development without sacrificing the animals.
authors.affiliation: Department of Cardiology, University of Vienna, Austria.
authors.forename: Georg
authors.initials: G
authors.lastname: Fröhlich
authors.forename: Christoph
authors.initials: C
authors.lastname: Strehblow
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Sperker
authors.forename: Nabil
authors.initials: N
authors.lastname: Yahya
authors.forename: Maryam
authors.initials: M
authors.lastname: Shirazi
authors.forename: Akos
authors.initials: A
authors.lastname: Hevesi
authors.forename: Rita
authors.initials: R
authors.lastname: Garamvölgyi
authors.forename: Janaki
authors.initials: J
authors.lastname: Hadjiev
authors.forename: Thomas
authors.initials: T
authors.lastname: Scherzer
authors.forename: Dietmar
authors.initials: D
authors.lastname: Glogar
authors.forename: Mariann
authors.initials: M
authors.lastname: Gyöngyösi
mesh_terms: D000818:Animals; D017023:Coronary Angiography; D003331:Coronary Vessels / Q000000981:diagnostic imaging* / Q000473:pathology; D006965:Hyperplasia; D010865:Pilot Projects; D015607:Stents; D013552:Swine; D017539:Tunica Intima / Q000473:pathology; D018084:Ultrasonography, Interventional