title: Effects of metal coverage rate of flow diversion device on neointimal growth at side branch ostium and stented artery: an animal experiment in rabbit abdominal aorta.
abstract: BACKGROUND
  To access the effect of actual metal coverage rate (MCR) on neointimal growth at covered side branch ostium and stented artery after implantation of a flow diversion device.
  
  
  METHODS
  Flow diverters (FDs) were implanted into abdominal aortas of 20 New Zealand rabbits. Four weeks and three months after FD implantation, the patency of side branches covered by the devices was assessed by angiography. The animals were sacrificed after angiography at 3 months postsurgery. The local actual MCR was measured under microscope and calculated. The extent of neointimal coverage at the ostia of branches and the neointima within the stent were examined by histology and scanning electron microscopy.
  
  
  RESULTS
  No side branch occlusion was noted, either immediately after implantation or at follow-ups. At 3 months after implantation, the intimal coverage of branch ostia caused by a 30-40% MCR was not significantly different from that caused by an MCR ≤ 30% (p = 0.792), but it was significantly lower than that caused by an MCR ≥ 40% (p = 0.021). Neointimal thickness in the stented abdominal aorta was positively correlated to MCR (r = 0.523, p = 0.001). The neointima was composed predominantly of smooth muscle cells and collagen fibers.
  
  
  CONCLUSIONS
  The actual MCR exhibited remarkable differences once FD was implanted in vivo. Significantly more intimal coverage at the side branch ostia could be induced when MCR was ≥40%. The neointimal thickness within the stent was positively correlated to device MCR.
authors.affiliation: Department of Neurosurgery, Changhai Hospital, Second Military Medical University, 168 Changhai Road, Shanghai, 200433, China.
authors.forename: Bo
authors.initials: B
authors.lastname: Hong
authors.forename: Kuizhong
authors.initials: K
authors.lastname: Wang
authors.forename: Qinghai
authors.initials: Q
authors.lastname: Huang
authors.forename: Yi
authors.initials: Y
authors.lastname: Xu
authors.forename: Xinggen
authors.initials: X
authors.lastname: Fang
authors.forename: Zhen
authors.initials: Z
authors.lastname: Li
authors.forename: Jianmin
authors.initials: J
authors.lastname: Liu
mesh_terms: D000792:Angiography; D000818:Animals; D001012:Aorta, Abdominal / Q000473:pathology* / Q000601:surgery; D016014:Linear Models; D008670:Metals; D008855:Microscopy, Electron, Scanning; D023421:Models, Animal; D058426:Neointima / Q000473:pathology*; D011817:Rabbits; D015607:Stents; D014654:Vascular Patency
chemical_list: D008670:Metals