title: Histopathologic insight into saphenous vein bypass graft disease.
abstract: OBJECTIVE
  Vein graft disease is a major drawback of coronary artery bypass grafting. However, histopathologic studies of old human aortocoronary grafts are scarce.
  
  
  METHODS
  We screened patients undergoing redo coronary artery bypass grafting at three university hospitals and selected those with at least one excisable old vein graft. Native non-grafted saphenous veins were also obtained as controls. Clinical and angiographic data were separately documented.
  
  
  RESULTS
  We evaluated 117 segments from 29 veins. All but 4 old graft segments showed degrees of luminal narrowing and fibrointimal proliferation. Moreover, 61 segments demonstrated atherosclerotic plaques. Such plaques were typically concentric and, compared with other segments, more frequently represented necrosis, calcification and giant cells (p < 0.001 for all comparisons) and had a higher inflammatory cell count, predominantly of lymphocytic origin. Native saphenous veins frequently showed fibrosis, but no calcification or active inflammation. Angiographic findings showed moderate correlation with the histological degree of luminal stenosis (Spearman's ρ = 0.564, p < 0.001).
  
  
  CONCLUSIONS
  Human vein graft atherosclerosis and arterial atherosclerosis share many features; however, we found lymphocytes to be the dominant inflammatory cells within plaques. Conventional angiography underestimated the atherosclerosis burden in vein grafts. Improved understanding of disease pathophysiology could lead to the development of novel interventions that reduce costly and suboptimal repeat revascularizations.
authors.affiliation: Cardiovascular Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Behnood
authors.initials: B
authors.lastname: Bikdeli
authors.forename: Seyed-Ahmad
authors.initials: SA
authors.lastname: Hassantash
authors.forename: Mihan
authors.initials: M
authors.lastname: Pourabdollah
authors.forename: Shadi
authors.initials: S
authors.lastname: Kalantarian
authors.forename: Maryam
authors.initials: M
authors.lastname: Sadeghian
authors.forename: Haleh
authors.initials: H
authors.lastname: Afshar
authors.forename: Shahram
authors.initials: S
authors.lastname: Sabeti
authors.forename: Mehrab
authors.initials: M
authors.lastname: Marzban
authors.forename: Hossein
authors.initials: H
authors.lastname: Ahmadi
authors.forename: Foroozan
authors.initials: F
authors.lastname: Mohammadi
mesh_terms: D050197:Atherosclerosis / Q000473:pathology*; D001026:Coronary Artery Bypass; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D058226:Plaque, Atherosclerotic / Q000473:pathology*; D011183:Postoperative Complications / Q000473:pathology*; D011446:Prospective Studies; D012086:Reoperation; D012501:Saphenous Vein / Q000473:pathology* / Q000637:transplantation; D019737:Transplants