title: Outcome after occlusion of infrainguinal bypasses in the Dutch BOA Study: comparison of amputation rate in venous and prosthetic grafts.
abstract: OBJECTIVE
  To compare the consequences of occlusion of infrainguinal venous and prosthetic grafts.
  
  
  METHODS
  In total, 2690 patients were included in the Dutch BOA study, a multicenter randomised trial that compared the effectiveness of oral anticoagulants with aspirin in the prevention of infrainguinal bypass graft occlusion. Two thousand four hundred and four patients received a femoropopliteal or femorodistal bypass with a venous (64%) or prosthetic (36%) graft. The incidence of occlusion and amputation was calculated according to graft material and the incidence of amputation after occlusion was compared with Cox regression to adjust for differences in prognostic factors.
  
  
  RESULTS
  The indication for operation was claudication in 51%, rest pain in 20% and tissue loss in 28% of patients. The mean follow up was 21 months. After venous bypass grafting 171 (15%) femoropopliteal and 96 (24%) femorodistal grafts occluded. After prosthetic bypass grafting 234 (30%) femoropopliteal and 25 (38%) femorodistal grafts occluded. Patients with occlusions in the venous group had more severe ischemia, less runoff vessels and were older than the patients with prosthetic grafts. In the venous occlusion group 54 (20%) amputations were performed compared to 42 (16%) in the prosthetic occlusion group; crude hazard ratio 1.17 (95% CI 0.78-1.75). After adjustment for above mentioned differences in patient characteristics the hazard ratio was 0.86 (95% CI 0.56-1.32).
  
  
  CONCLUSIONS
  The need for amputation after occlusion is not influenced by graft material in infrainguinal bypass surgery.
authors.affiliation: Department of Surgery, Twenteborg Hospital, Almelo, The Netherlands. smeets_luuk@hotmail.com
authors.forename: L
authors.initials: L
authors.lastname: Smeets
authors.forename: G H
authors.initials: GH
authors.lastname: Ho
authors.forename: M J D
authors.initials: MJ
authors.lastname: Tangelder
authors.forename: A
authors.initials: A
authors.lastname: Algra
authors.forename: J A
authors.initials: JA
authors.lastname: Lawson
authors.forename: B C
authors.initials: BC
authors.lastname: Eikelboom
authors.forename: F L
authors.initials: FL
authors.lastname: Moll
mesh_terms: D000368:Aged; D000671:Amputation, Surgical / Q000706:statistics & numerical data*; D001157:Arterial Occlusive Diseases / Q000601:surgery*; D001807:Blood Vessel Prosthesis; D019917:Blood Vessel Prosthesis Implantation / Q000295:instrumentation*; D005260:Female; D005500:Follow-Up Studies; D006083:Graft Occlusion, Vascular / Q000453:epidemiology / Q000209:etiology* / Q000601:surgery; D006801:Humans; D015994:Incidence; D007264:Inguinal Canal; D008297:Male; D009426:Netherlands / Q000453:epidemiology; D011150:Popliteal Artery / Q000000981:diagnostic imaging / Q000601:surgery*; D011475:Prosthesis Failure; D012086:Reoperation; D012189:Retrospective Studies; D012307:Risk Factors; D012501:Saphenous Vein / Q000637:transplantation; D016896:Treatment Outcome; D018608:Ultrasonography, Doppler