title: Uncovered stent does not provoke reactions in renal arteries and renal parenchyma in swines.
abstract: OBJECTIVE
  To assess the histological changes of the aorta, the renal arteries and the renal parenchyma in swine, induced by a metalic uncovered stent implanted in transrenal position in the abdominal aorta.
  
  
  METHODS
  Ten pigs with a mean weight of 86.6 kg and mean age of 6 months underwent implantation of metal stent graft placed in the aorta at the level of the renal arteries after 100 days of implantation. The self-expanding stents were released by laparotomy. Anatomic and histological analyses of the abdominal aorta, the renal arteries and the renal parenchyma were performed. Histological slices were performed in the following sites: 1) transitional zone between the aorta with and without stent graft; 2) portion of the renal arteries ostia; 3) renal parenchyma. The slices were stained through the hematoxylin and eosin stain technique and analyzed according the protocol of histological analyses applied in the clinical practice of pathology labs.
  
  
  RESULTS
  The macroscopic findings showed thickening of the aortic wall; patent renal arteries; and normal anatomic renal structures. Microscopic analyses, close to the stents, showed thickening of the vascular wall, renal arteries without changes, and preserved renal parenchyma.
  
  
  CONCLUSIONS
  The uncovered stainless steel stent caused a significant inflammatory reaction with thickening of the aortic wall. However, the renal arteries remained patent and the renal parenchyma did not present embolic or ischemic changes.
authors.affiliation: Hospital Maternidade Marieta Konder Bonhausem, Itajaí, SC. rubiobombonato@terra.com.br
authors.forename: Rubio
authors.initials: R
authors.lastname: Bombonato
authors.forename: José Honório
authors.initials: JH
authors.lastname: Palma
authors.forename: José Augusto
authors.initials: JA
authors.lastname: Marcondes
authors.forename: Aury Nunes de
authors.initials: AN
authors.lastname: Moraes
authors.forename: João Luiz da
authors.initials: JL
authors.lastname: Rocha
authors.forename: Marcio Rodrigo
authors.initials: MR
authors.lastname: Martins
authors.forename: Rodrigo Mezzalira
authors.initials: RM
authors.lastname: Tchaick
authors.forename: Enio
authors.initials: E
authors.lastname: Buffolo
mesh_terms: D000818:Animals; D001012:Aorta, Abdominal / Q000473:pathology* / Q000601:surgery; D001807:Blood Vessel Prosthesis / Q000009:adverse effects*; D019917:Blood Vessel Prosthesis Implantation / Q000379:methods; D005549:Foreign-Body Reaction / Q000473:pathology*; D007249:Inflammation / Q000473:pathology; D007668:Kidney / Q000473:pathology*; D023421:Models, Animal; D011474:Prosthesis Design / Q000009:adverse effects; D012077:Renal Artery / Q000473:pathology*; D012078:Renal Artery Obstruction / Q000473:pathology; D015607:Stents / Q000009:adverse effects*; D013552:Swine