Uncovered stent does not provoke reactions in renal arteries and renal parenchyma in swines.
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.
Bombonato
Rubio
R
Hospital Maternidade Marieta Konder Bonhausem, Itajaí, SC. rubiobombonato@terra.com.br
Palma
José Honório
JH
Marcondes
José Augusto
JA
Moraes
Aury Nunes de
AN
Rocha
João Luiz da
JL
Martins
Marcio Rodrigo
MR
Tchaick
Rodrigo Mezzalira
RM
Buffolo
Enio
E
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