title: Marked inflammatory sequelae to implantation of biodegradable and nonbiodegradable polymers in porcine coronary arteries.
abstract: BACKGROUND
  With the thrombogenic tendency and permanent implant nature of metallic stents, synthetic polymers have been proposed as candidate materials for stents and local drug delivery designs. We investigated the biocompatibility of several synthetic polymers after experimental placement in the coronary artery.
  
  
  RESULTS
  Five different biodegradable polymers (polyglycolic acid/polylactic acid [PGLA], polycaprolactone [PCL], polyhydroxybutyrate valerate [PHBV], polyorthoester [POE], and polyethyleneoxide/polybutylene terephthalate [PEO/ PBTP]) and three nonbiodegradable polymers (polyurethane [PUR], silicone [SIL], and polyethylene terephthalate [PETP]) were tested as strips deployed longitudinally across 90 degrees of the circumferential surface of coil wire stents. Appropriately sized polymer-loaded stents were implanted in porcine coronary arteries of 2.5- to 3.0-mm diameter. Four weeks after implantation, stent patency was assessed by angiography followed by microscopic examination of the coronary arteries. The biodegradable PCL, PHBV, and POE and the nonbiodegradable PUR and SIL evoked extensive inflammatory responses and fibrocellular proliferation (thickness of tissue response: 0.79 +/- 0.22, 1.12 +/- 0.01, 2.36 +/- 0.60, 1.24 +/- 0.36, and 1.43 +/- 0.15 mm, respectively). Less but still severe responses were observed for the biodegradable PGLA and PEO/PBTP (0.46 +/- 0.18 and 0.61 +/- 0.23 mm, respectively) and for the nonbiodegradable PETP (0.46 +/- 0.11 mm).
  
  
  CONCLUSIONS
  An array of both biodegradable and nonbiodegradable polymers has been demonstrated to induce a marked inflammatory reaction within the coronary artery with subsequent neointimal thickening, which was not expected on the basis of in vitro tests. The observed tissue response may be attributable to a combination of parent polymer compound, biodegradation products, and possibly implant geometry.
authors.affiliation: Department of Cardiology, Erasmus University Rotterdam, The Netherlands.
authors.forename: W J
authors.initials: WJ
authors.lastname: van der Giessen
authors.forename: A M
authors.initials: AM
authors.lastname: Lincoff
authors.forename: R S
authors.initials: RS
authors.lastname: Schwartz
authors.forename: H M
authors.initials: HM
authors.lastname: van Beusekom
authors.forename: P W
authors.initials: PW
authors.lastname: Serruys
authors.forename: D R
authors.initials: DR
authors.lastname: Holmes
authors.forename: S G
authors.initials: SG
authors.lastname: Ellis
authors.forename: E J
authors.initials: EJ
authors.lastname: Topol
mesh_terms: D000818:Animals; D001158:Arteries / Q000473:pathology / Q000601:surgery; D001672:Biocompatible Materials; D001673:Biodegradation, Environmental; D017023:Coronary Angiography; D003331:Coronary Vessels / Q000473:pathology / Q000601:surgery*; D005500:Follow-Up Studies; D011108:Polymers; D019736:Prostheses and Implants / Q000009:adverse effects; D015607:Stents / Q000009:adverse effects; D013552:Swine; D014657:Vasculitis / Q000209:etiology / Q000473:pathology
chemical_list: D001672:Biocompatible Materials; D011108:Polymers