title: Tissue responses to stent grafts with endo-exo-skeleton for saccular abdominal aortic aneurysms in a canine model.
abstract: OBJECTIVE
  We evaluated the effect of close contact between the stent and the graft on the induction of endothelial covering on the stent graft placed over an aneurysm.
  
  
  METHODS
  Saccular abdominal aortic aneurysms were made with Dacron patch in eight dogs. The stent graft consisted of an inner stent, a expanded polytetrafluoroethylene graft, and an outer stent. After sacrificing the animals, the aortas with an embedded stent graft were excised. The aortas were inspected grossly and evaluated microscopically.
  
  
  RESULTS
  The animals were sacrificed at two (n = 3), six (n = 3), and eight months (n = 2) after endovascular repair. In two dogs, the aortic lumen was occluded at two months after the placement. On gross inspection of specimens from the other six dogs with a patent aortic lumen, stent grafts placed over the normal aortic wall were covered by glossy white neointima, whereas, stent grafts placed over the aneurysmal aortic wall were covered by brownish neointima. On microscopic inspection, stent grafts placed over the normal aortic wall were covered by thin neointima (0.27 ± 0.05 mm, mean ± standard deviation) with an endothelial layer, and stent grafts placed over the aneurysmal aortic wall were covered by thick neointima (0.62 ± 0.17 mm) without any endothelial lining. Transgraft cell migration at the normal aortic wall was more active than that at the aneurysmal aortic wall.
  
  
  CONCLUSIONS
  Close contact between the stent and the graft, which was achieved with stent grafts with endo-exo-skeleton, could not enhance endothelial covering on the stent graft placed over the aneurysms.
authors.affiliation: Department of Radiology and Institute of Radiation Medicine, Seoul National University College of Medicine, Clinical Research Institute, Seoul 110-744, Korea.
authors.forename: Young Il
authors.initials: YI
authors.lastname: Kim
authors.affiliation: Department of Radiology, Seoul National University Boramae Hospital, Seoul 156-707, Korea.
authors.forename: Young Ho
authors.initials: YH
authors.lastname: Choi
authors.affiliation: Department of Radiology and Institute of Radiation Medicine, Seoul National University College of Medicine, Clinical Research Institute, Seoul 110-744, Korea.
authors.forename: Jin Wook
authors.initials: JW
authors.lastname: Chung
authors.affiliation: Department of Radiology and Institute of Radiation Medicine, Seoul National University College of Medicine, Clinical Research Institute, Seoul 110-744, Korea.
authors.forename: Hyo-Cheol
authors.initials: HC
authors.lastname: Kim
authors.affiliation: Department of Radiology, Seoul National University Boramae Hospital, Seoul 156-707, Korea.
authors.forename: Young Ho
authors.initials: YH
authors.lastname: So
authors.affiliation: Department of Radiology, National Cancer Center, Goyang 410-769, Korea.
authors.forename: Hyun Beom
authors.initials: HB
authors.lastname: Kim
authors.affiliation: Department of Surgery, Seoul National University College of Medicine, Seoul 110-744, Korea.
authors.forename: Seung-Kee
authors.initials: SK
authors.lastname: Min
authors.affiliation: Department of Radiology, Gachon University Gil Medical Center, Incheon 405-760, Korea.
authors.forename: Jae Hyung
authors.initials: JH
authors.lastname: Park
mesh_terms: D000818:Animals; D017544:Aortic Aneurysm, Abdominal / Q000473:pathology / Q000628:therapy*; D019917:Blood Vessel Prosthesis Implantation; D004195:Disease Models, Animal; D004285:Dogs; D004730:Endothelium, Vascular / Q000166:cytology / Q000473:pathology; D015607:Stents; D014057:Tomography, X-Ray Computed
keywords: Aorta; Aortic aneurysm; Endothelium; Neointima; Stent-graft