title: Safety and efficacy of antiplatelet/anticoagulation regimens after Viabahn stent graft treatment for femoropopliteal occlusive disease.
abstract: OBJECTIVE
  We aimed to determine the safety and efficacy of antiplatelet/anticoagulation regimens after placement of Viabahn stent graft (W. L. Gore & Associates, Flagstaff, Ariz) for the treatment of femoropopliteal occlusive disease.
  
  
  METHODS
  Clinical, angiographic, and procedural data for patients undergoing endovascular treatment of femoropopliteal occlusive disease using Viabahn covered stent grafts at a single institution between 2006 and 2013 were retrospectively reviewed. Graft patency and freedom from thrombolysis, major adverse limb event, and reintervention were determined by Kaplan-Meier analysis. The influence of relevant variables on clinical outcome was determined through univariate and multivariate Cox proportional hazards analyses.
  
  
  RESULTS
  Viabahn stent grafts were placed in a total of 91 limbs in 61 patients (66% men; mean age, 69 ± 12 years) during the study period. Indication for intervention was either claudication (n = 59) or critical limb ischemia (n = 32), with the majority (70%) classified as TransAtlantic Inter-Society Consensus II C (n = 33) or D (n = 31) lesions. Mean follow-up was 38.3 months (range, 1-91 months). Postprocedural pharmacologic regimens included aspirin, clopidogrel, and warfarin (47%); indefinite aspirin and clopidogrel (46%); or aspirin and temporary clopidogrel (7%). Primary and secondary patency rates were 60%, 44%, and 36% and 95%, 82%, and 74% at 1 year, 3 years, and 5 years, respectively. Kaplan-Meier analysis demonstrated more aggressive antiplatelet/anticoagulation regimens to be associated with improved primary patency and freedom from reintervention. Cox proportional hazards analysis demonstrated TransAtlantic Inter-Society Consensus II D lesions, tobacco use, coronary artery disease, and smaller stent diameter to be independent risk factors for stent graft failure. Bleeding events were limited to those in the aspirin, clopidogrel, and warfarin group (11.6% [n = 5]; P = .052), although the majority of these events were not life-threatening, and only two cases required blood transfusion.
  
  
  CONCLUSIONS
  Increasingly aggressive antithrombotic regimens after Viabahn stent graft placement trended toward improved overall clinical outcomes, although the marginal patency benefit observed with the addition of warfarin to dual antiplatelet therapy was tempered by an observed increased risk of bleeding complications. Longer term follow-up and multicenter studies are needed to further define optimal type and duration of antithrombotic therapy after endovascular peripheral interventions.
authors.affiliation: Division of Vascular Surgery, Stanford University Medical Center, Stanford, Calif.
authors.forename: Brant W
authors.initials: BW
authors.lastname: Ullery
authors.affiliation: Division of Vascular Surgery, Stanford University Medical Center, Stanford, Calif.
authors.forename: Kenneth
authors.initials: K
authors.lastname: Tran
authors.affiliation: Division of Vascular Surgery, Stanford University Medical Center, Stanford, Calif.
authors.forename: Nathan
authors.initials: N
authors.lastname: Itoga
authors.affiliation: Division of Vascular Surgery, Stanford University Medical Center, Stanford, Calif.
authors.forename: Kevin
authors.initials: K
authors.lastname: Casey
authors.affiliation: Division of Vascular Surgery, Stanford University Medical Center, Stanford, Calif.
authors.forename: Ronald L
authors.initials: RL
authors.lastname: Dalman
authors.affiliation: Division of Vascular Surgery, Stanford University Medical Center, Stanford, Calif. Electronic address: jtlee@stanford.edu.
authors.forename: Jason T
authors.initials: JT
authors.lastname: Lee
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000925:Anticoagulants / Q000009:adverse effects / Q000627:therapeutic use*; D001807:Blood Vessel Prosthesis; D019917:Blood Vessel Prosthesis Implantation / Q000009:adverse effects / Q000295:instrumentation*; D002140:California; D016009:Chi-Square Distribution; D003251:Constriction, Pathologic; D018572:Disease-Free Survival; D004359:Drug Therapy, Combination; D057510:Endovascular Procedures / Q000009:adverse effects / Q000295:instrumentation*; D005263:Femoral Artery / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D006083:Graft Occlusion, Vascular / Q000209:etiology / Q000503:physiopathology / Q000517:prevention & control; D006470:Hemorrhage / Q000139:chemically induced; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D058729:Peripheral Arterial Disease / Q000175:diagnosis / Q000503:physiopathology / Q000601:surgery*; D010975:Platelet Aggregation Inhibitors / Q000009:adverse effects / Q000627:therapeutic use*; D011150:Popliteal Artery / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D016016:Proportional Hazards Models; D011474:Prosthesis Design; D011859:Radiography; D012189:Retrospective Studies; D012307:Risk Factors; D015607:Stents; D013927:Thrombosis / Q000209:etiology / Q000503:physiopathology / Q000517:prevention & control; D013997:Time Factors; D016896:Treatment Outcome; D014654:Vascular Patency
chemical_list: D000925:Anticoagulants; D010975:Platelet Aggregation Inhibitors