title: Effect of external stents on prevention of intimal hyperplasia in a canine vein graft model.
abstract: BACKGROUND
  External stents have been used to reduce intimal hyperplasia of vein grafts. The aim of the present study was to define the size of an external stent appropriate for a particular graft by comparing vein grafts with different sizes of external stents.
  
  
  METHODS
  A series of paired trials was performed to compare femoral vein grafts with different sizes of external stents, where 30 modeled canines were equally divided into three groups: 6-mm external stent vs non-stent control, 4-mm vs 6-mm external stent, and 4-mm vs 8-mm external stent. At day 3 after operation, color Doppler flow imaging (CDFI) was done to observe blood flow in the lumen. Four weeks later, CDFI was re-checked and the veins were harvested, stained and measured.
  
  
  RESULTS
  All grafts were patent without formation of thrombosis. External stents significantly reduced intimal thickness of the vein grafts with a 6-mm external stent compared with the vein grafts without external stents (P < 0.05). The vein grafts with the 4-mm external stent had similar intimal, medial and adventitial thicknesses compared with those with the 6-mm external stent and the 8-mm external stent.
  
  
  CONCLUSIONS
  External stents can reduce intimal hyperplasia of vein grafts. Stents of different diameters exert the similar effect on prevention of intimal hyperplasia.
authors.affiliation: Department of Cardiothoracic Surgery, Changhai Hospital, Second Military Medical University, Shanghai 200433, China.
authors.forename: Rong-jiang
authors.initials: RJ
authors.lastname: Zou
authors.forename: Liang-jian
authors.initials: LJ
authors.lastname: Zou
authors.forename: Sheng-dong
authors.initials: SD
authors.lastname: Huang
authors.forename: Yin
authors.initials: Y
authors.lastname: Wang
authors.forename: Lin
authors.initials: L
authors.lastname: Han
authors.forename: Guang-yu
authors.initials: GY
authors.lastname: Ji
authors.forename: Zhi-yun
authors.initials: ZY
authors.lastname: Xu
mesh_terms: D000818:Animals; D001241:Aspirin / Q000627:therapeutic use; D004285:Dogs; D005268:Femoral Vein / Q000637:transplantation*; D006965:Hyperplasia; D015607:Stents; D017539:Tunica Intima / Q000473:pathology*; D018615:Ultrasonography, Doppler, Color
chemical_list: D001241:Aspirin