title: Quantification of Adventitial Vasa Vasorum Vascularization in Double-injury Restenotic Arteries.
abstract: BACKGROUND
  Accumulating evidence indicates a potential role of adventitial vasa vasorum (VV) dysfunction in the pathophysiology of restenosis. However, characterization of VV vascularization in restenotic arteries with primary lesions is still missing. In this study, we quantitatively evaluated the response of adventitial VV to vascular injury resulting from balloon angioplasty in diseased arteries.
  
  
  METHODS
  Primary atherosclerotic-like lesions were induced by the placement of an absorbable thread surrounding the carotid artery of New Zealand rabbits. Four weeks following double-injury induced that was induced by secondary balloon dilation, three-dimensional patterns of adventitial VV were reconstructed; the number, density, and endothelial surface of VV were quantified using micro-computed tomography. Histology and immunohistochemistry were performed in order to examine the development of intimal hyperplasia.
  
  
  RESULTS
  Results from our study suggest that double injured arteries have a greater number of VV, increased luminal surface, and an elevation in the intima/media ratio (I/M), along with an accumulation of macrophages and smooth muscle cells in the intima, as compared to sham or single injury arteries. I/M and the number of VV were positively correlated (R2 = 0.82, P < 0.001).
  
  
  CONCLUSIONS
  Extensive adventitial VV neovascularization occurs in injured arteries after balloon angioplasty, which is associated with intimal hyperplasia. Quantitative assessment of adventitial VV response may provide insight into the basic biological process of postangioplasty restenosis.
authors.forename: Meng
authors.initials: M
authors.lastname: Ye
authors.forename: Bai-Gen
authors.initials: BG
authors.lastname: Zhang
authors.forename: Lan
authors.initials: L
authors.lastname: Zhang
authors.forename: Hui
authors.initials: H
authors.lastname: Xie
authors.affiliation: Department of Vascular Surgery, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200127, China.
authors.forename: Hao
authors.initials: H
authors.lastname: Zhang
mesh_terms: D015906:Angioplasty, Balloon, Coronary; D000818:Animals; D008297:Male; D009389:Neovascularization, Pathologic / Q000175:diagnosis*; D011817:Rabbits; D014651:Vasa Vasorum / Q000502:physiology*; D055114:X-Ray Microtomography