title: Histologic evaluation of platinum coil embolization in an aneurysm model in rabbits.
abstract: OBJECTIVE
  To characterize the histologic response to platinum coil embolization by using a rabbit aneurysm model.
  
  
  METHODS
  Saccular aneurysms were created in New Zealand White rabbits by using vessel ligation with intraluminal elastase incubation. Aneurysms were subsequently embolized by using platinum coils. Subjects were sacrificed at various intervals up to 12 weeks following coil embolization. The aneurysm cavities and adjacent vessels were embedded in methylmethacrylate, were sectioned, and were stained for histologic examination.
  
  
  RESULTS
  Two weeks following coil implantation, aneurysms were filled predominantly with unorganized thrombus. Six weeks following coil implantation, histologic features included complete filling of the aneurysm lumen with either prominent laminated but unorganized thrombus or areas of unorganized thrombus interspersed among areas of cellular infiltration. At 12 weeks following coil implantation, aneurysms were filled with the loosely packed, disordered cells contained within the extracellular matrix. Fibrosis or smooth muscle cell infiltration was not present in any of the 6- or 12-week samples.
  
  
  CONCLUSIONS
  Platinum coils placed into experimental saccular aneurysms in New Zealand White rabbits failed to elicit a fibrotic response. This model can be used for the testing of biologic modifications of platinum coils aimed at increasing intra-aneurysmal fibrosis.
authors.affiliation: Department of Radiology, University of Virginia Health Services, Charlottesville 22908, USA. dfk3b@virginia.edu
authors.forename: D F
authors.initials: DF
authors.lastname: Kallmes
authors.forename: G A
authors.initials: GA
authors.lastname: Helm
authors.forename: S B
authors.initials: SB
authors.lastname: Hudson
authors.forename: T A
authors.initials: TA
authors.lastname: Altes
authors.forename: H M
authors.initials: HM
authors.lastname: Do
authors.forename: J W
authors.initials: JW
authors.lastname: Mandell
authors.forename: H J
authors.initials: HJ
authors.lastname: Cloft
mesh_terms: D000818:Animals; D002340:Carotid Artery Diseases / Q000473:pathology / Q000628:therapy*; D017536:Carotid Artery, Common / Q000000981:diagnostic imaging / Q000473:pathology; D004621:Embolization, Therapeutic / Q000295:instrumentation* / Q000379:methods; D002532:Intracranial Aneurysm / Q000000981:diagnostic imaging / Q000473:pathology / Q000628:therapy*; D010984:Platinum; D011817:Rabbits; D011859:Radiography
chemical_list: D010984:Platinum