title: Extraluminal atherosclerosis: an under-recognised finding in human aortocoronary venous bypass grafts.
abstract: BACKGROUND
  Coronary artery bypass grafting (CABG) is commonly compromised by graft atherosclerosis. Histopathologic studies confirm various forms of atherosclerosis, including positively remodelled lesions in native coronary arteries but there are no histopathologic reports of extraluminal atherosclerosis in vein grafts.
  
  
  METHODS
  We prospectively investigated the histopathologic presence and pattern of extraluminal atherosclerosis in human old vein grafts in a two-year interval among patients undergoing redo-CABG at three university hospitals in Tehran. We separately documented clinical and angiographic findings.
  
  
  RESULTS
  We evaluated 100 segments from 20 human old vein grafts obtained during the redo CABG. All but four segments demonstrated some degrees of luminal narrowing. Luminal atherosclerotic plaques were detectable in 61 segments. We detected extraluminal atheroscleoris in seven segments. Mean vessel wall thickness was greater in segments containing extraluminal plaques (1.41±0.26 mm versus 0.91±0.04 mm, P=0.008). Angiographic findings had a modest correlation with presence or absence of luminal atheromatous lesions (Spearman's rho: 0.331, P=0.007). Angiographic degree of stenosis could not predict the presence of positively remodelled atherosclerotic plaques (Spearman's rho: -2.21, P=0.073).
  
  
  CONCLUSIONS
  Previous studies suggested positive remodelling in vein grafts. Out study provides histopathologic evidence on extraluminal atherosclerosis in human aortocoronary vein grafts.
authors.affiliation: Pediatric Respiratory Diseases Research Center, NRITLD, Masih Daneshvari Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Mihan
authors.initials: M
authors.lastname: Pourabdollah
authors.forename: Seyed-Ahmad
authors.initials: SA
authors.lastname: Hasssantash
authors.forename: Behnood
authors.initials: B
authors.lastname: Bikdeli
authors.forename: Maryam
authors.initials: M
authors.lastname: Sadeghian
authors.forename: Haleh
authors.initials: H
authors.lastname: Afshar
authors.forename: Shadi
authors.initials: S
authors.lastname: Kalantarian
authors.forename: Shahram
authors.initials: S
authors.lastname: Sabeti
authors.forename: Hossein
authors.initials: H
authors.lastname: Ahmadi
authors.forename: Mehrab
authors.initials: M
authors.lastname: Marzban
authors.forename: Foroozan
authors.initials: F
authors.lastname: Mohammadi
mesh_terms: D017023:Coronary Angiography; D001026:Coronary Artery Bypass; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging* / Q000209:etiology / Q000503:physiopathology / Q000601:surgery; D005260:Female; D006083:Graft Occlusion, Vascular / Q000000981:diagnostic imaging* / Q000503:physiopathology / Q000601:surgery; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D013997:Time Factors