Aury Nunes de MORAES

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 8. Full Professor (Titular Professor of the Cardiovascular Surgery Discipline of UNIFESP – Paulista Medical School, SP). This study was carried out at the Hospital and Maternity Marieta Konder Bornhausen, Itajaí, SC. Correspondence address: Rubio Bombonato. R. 1901, 111, apto. 803. Balneário Camboriú, SC. CEP 88330-819. Email: [email protected] Article received on September 17th, 2008 Article accepted on June 5th 2009 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. Conclusion: 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. Descriptors: Stents. Renal artery. Renal artery obstruction. Aorta, abdominal. Swine.