title: Biologic degeneration of vein grafts after thrombotic occlusion: thrombectomy within 3 days results in better indices of viability.
abstract: OBJECTIVE
  To clarify the mechanism for poor patency of vein grafts after thrombectomy and the time limit for successful salvage operation, we investigated the time course of biologic degenerative changes in thrombosed vein grafts. Materials and methods The right femoral artery was replaced with a femoral vein graft in 25 mongrel dogs. After 3 months, grafts were explanted in 5 dogs (control grafts), and the remaining 20 dogs underwent femoral artery ligation to create a thrombosed graft. Of the 20 grafts, 5 were explanted at 3 days after ligation (group I-3) and 5 were explanted at 5 days after ligation (group I-5). Of the remaining 10 grafts, 5 underwent thrombectomy at 3 days after ligation (group II-3) and 5 underwent thrombectomy at 5 days after ligation, and were reimplanted into the left femoral artery, then explanted 28 days after reimplantation. The grafts were assessed with immunohistochemistry and prostaglandin (PG) I(2) assay (6-keto-PGI(1alpha)).
  
  
  RESULTS
  Of the 25 grafts, occlusion recurred in 3 in group II-5 within 28 days after reimplantation. There were significant differences between group I-5 and group I-3 or control grafts for percentage of areas positive for alpha-actin, total number of cells per field, and proliferating cell nuclear antigen (PCNA)-positive cells in layer of thickened intima and atrophied media (I/M), and for total cell and PCNA- positive cell numbers per field in the adventitia. Mean 6-ketoPGF(1alpha) was 40 +/- 14.1 pg/mg/min in control dogs, 84 +/- 18.9 pg/mg/min in group I-3, and 15.4 +/- 7.7 pg/mg/min in group I-5, demonstrating a significant reduction in group I-5 (P =.009).
  
  
  CONCLUSIONS
  Graft wall cell viability and PGI(2) production in thrombosed vein grafts are well preserved for up to 3 days. Therefore graft salvage operations no later than 3 days after thrombotic occlusion may provide acceptable long-term patency of salvaged grafts.
authors.affiliation: Department of Surgery, Asahikawa Medical University, 2-3 Midorigaoka, Higashi, Asahikawa 078-8307, Japan.
authors.forename: Shigehisa
authors.initials: S
authors.lastname: Kawai
authors.forename: Tadahiro
authors.initials: T
authors.lastname: Sasajima
authors.forename: Keisuke
authors.initials: K
authors.lastname: Satoh
authors.forename: Masashi
authors.initials: M
authors.lastname: Inaba
authors.forename: Nobuyoshi
authors.initials: N
authors.lastname: Azuma
authors.forename: Kosuke
authors.initials: K
authors.lastname: Yamazaki
authors.forename: Kensuke
authors.initials: K
authors.lastname: Oikawa
mesh_terms: D000818:Animals; D001807:Blood Vessel Prosthesis / Q000009:adverse effects*; D002470:Cell Survival / Q000502:physiology; D004285:Dogs; D004730:Endothelium, Vascular / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology; D011464:Epoprostenol / Q000096:biosynthesis; D005260:Female; D005263:Femoral Artery / Q000601:surgery; D006083:Graft Occlusion, Vascular / Q000209:etiology / Q000503:physiopathology*; D008297:Male; D017131:Thrombectomy; D013997:Time Factors; D014654:Vascular Patency / Q000502:physiology*; D014680:Veins / Q000473:pathology* / Q000601:surgery; D020246:Venous Thrombosis / Q000209:etiology / Q000378:metabolism / Q000473:pathology* / Q000601:surgery*
chemical_list: D011464:Epoprostenol