title: Biologic characteristics of long-term autogenous vein grafts: a dynamic evolution.
abstract: OBJECTIVE
  The venous conduit as an arterial substitute has dynamic biologic properties that affect its durability. This study evaluated the morphologic and physiologic characteristics of 72 lower extremity vein grafts functioning at 4.5 to 21.6 years (median 6.6 years).
  
  
  METHODS
  The entire graft was imaged with use of color duplex ultrasonography and then classified as normal (class I), abnormal but not graft-threatening (class II), or abnormal and graft-threatening (class III) for the proximal, middle, and distal thirds. Thirty-one grafts (43%) were classified as normal, whereas 41 (57%) were classified as abnormal, with 58 class II and 15 class III segments.
  
  
  RESULTS
  Three types of abnormalities were found by duplex imaging: nonstenotic wall plaques, discrete stenoses, and aneurysmal dilation. Aneurysms developed in five of seven grafts that had required thrombectomy in the distant past (mean of 40 months). There were 70 postoperative revisions in 38 limbs (53%). In 23 (60%) the conduit was revised, in 11 (29%) the revisions corrected progression of native artery atherosclerotic disease, and in 4 (11%) both types of revisions were required. Eleven grafts were revised in the first 30 days to correct technical errors. Eighteen limbs were revised between 1 and 24 months, with 12 (67%) of the revisions correcting stenotic lesions in the conduit or at one of the anastomoses. After 24 months 12 (67%) of 18 limbs were revised to correct progression of occlusive disease in the inflow or outflow vessels. At the time of this study 18 (67%) of the 27 conduits revised for intrinsic lesions were abnormal by color duplex imaging, and they harbored 12 (80%) of the 15-graft-threatening lesions.
  
  
  CONCLUSIONS
  Autogenous vein remains the most durable arterial conduit, but vigilant surveillance is essential because the atherosclerotic environment continually produces lesions that may imperil the longevity of the graft.
authors.affiliation: Division of Vascular Surgery, Medical College of Wisconsin, Milwaukee 53226.
authors.forename: T
authors.initials: T
authors.lastname: Reifsnyder
authors.forename: J B
authors.initials: JB
authors.lastname: Towne
authors.forename: G R
authors.initials: GR
authors.lastname: Seabrook
authors.forename: J F
authors.initials: JF
authors.lastname: Blair
authors.forename: D F
authors.initials: DF
authors.lastname: Bandyk
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001783:Blood Flow Velocity; D016009:Chi-Square Distribution; D003116:Color; D005260:Female; D005500:Follow-Up Studies; D006083:Graft Occlusion, Vascular / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D012086:Reoperation / Q000706:statistics & numerical data; D012307:Risk Factors; D012501:Saphenous Vein / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000637:transplantation*; D013997:Time Factors; D014182:Transplantation, Autologous; D014463:Ultrasonography