title: Comparison of graft patency, limb salvage, and antithrombotic therapy between prosthetic and autogenous below-knee bypass for critical limb ischemia.
abstract: BACKGROUND
  The autogenous vein is the preferred conduit in below-knee vascular reconstructions. However, many argue that prosthetic grafts can perform well in crural bypass with adjunctive antithrombotic therapy. We therefore compared outcomes of below-knee prosthetic versus autologous vein bypass grafts for critical limb ischemia and the use of adjunctive antithrombotic therapy in both settings.
  
  
  METHODS
  Utilizing the registry of the Vascular Study Group of New England (2003-2009), we studied 1227 patients who underwent below-knee bypass for critical limb ischemia, 223 of whom received a prosthetic graft to the below-knee popliteal artery (70%) or more distal target (30%). We used propensity matching to identify a patient cohort receiving single-segment saphenous vein yet had remained similar to the prosthetic cohort in terms of characteristics, graft origin/target, and antithrombotic regimen. Main outcome measures were graft patency and major limb amputation within 1 year. Secondary outcomes were bleeding complications (reoperation or transfusion) and mortality. We performed comparisons by conduit type and by antithrombotic therapy.
  
  
  RESULTS
  Patients receiving prosthetic conduit were more likely to be treated with warfarin than those with greater saphenous vein (57% vs. 24%, P<0.001). After propensity score matching, we found no significant difference in primary graft patency (72% vs. 73%, P=0.81) or major amputation rates (17% vs. 13%, P=0.31) between prosthetic and single-segment saphenous vein grafts. In a subanalysis of grafts to tibial versus popliteal targets, we noted equivalent primary patency and amputation rates between prosthetic and venous conduits. Whereas overall 1-year prosthetic graft patency rates varied from 51% (aspirin+clopidogrel) to 78% (aspirin+warfarin), no significant differences were seen in primary patency or major amputation rates by antithrombotic therapy (P=0.32 and 0.17, respectively). Further, the incidence of bleeding complications and 1-year mortality did not differ by conduit type or antithrombotic regimen in the propensity-matched analysis.
  
  
  CONCLUSIONS
  Although limited in size, our study demonstrates that, with appropriate patient selection and antithrombotic therapy, 1-year outcomes for below-knee prosthetic bypass grafting can be comparable to those for greater saphenous vein conduit.
authors.affiliation: Division of Vascular Surgery, University of Utah School of Medicine, Salt Lake City, UT. Electronic address: bjoern.suckow@hsc.utah.edu.
authors.forename: Bjoern D
authors.initials: BD
authors.lastname: Suckow
authors.forename: Larry W
authors.initials: LW
authors.lastname: Kraiss
authors.forename: David H
authors.initials: DH
authors.lastname: Stone
authors.forename: Andres
authors.initials: A
authors.lastname: Schanzer
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Bertges
authors.forename: Donald T
authors.initials: DT
authors.lastname: Baril
authors.forename: Jack L
authors.initials: JL
authors.lastname: Cronenwett
authors.forename: Philip P
authors.initials: PP
authors.lastname: Goodney
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001803:Blood Transfusion; D001807:Blood Vessel Prosthesis; D019917:Blood Vessel Prosthesis Implantation / Q000009:adverse effects / Q000295:instrumentation* / Q000401:mortality; D016638:Critical Illness; D005260:Female; D005343:Fibrinolytic Agents / Q000627:therapeutic use*; D006083:Graft Occlusion, Vascular / Q000209:etiology / Q000503:physiopathology / Q000517:prevention & control; D006801:Humans; D007511:Ischemia / Q000175:diagnosis / Q000401:mortality / Q000503:physiopathology / Q000601:surgery*; D053208:Kaplan-Meier Estimate; D007866:Leg / Q000098:blood supply*; D023821:Limb Salvage; D008297:Male; D008875:Middle Aged; D009511:New England; D018579:Patient Selection; D058729:Peripheral Arterial Disease / Q000175:diagnosis / Q000401:mortality / Q000503:physiopathology / Q000601:surgery*; D011138:Polytetrafluoroethylene; D019106:Postoperative Hemorrhage / Q000209:etiology / Q000628:therapy; D057216:Propensity Score; D011474:Prosthesis Design; D012042:Registries; D012086:Reoperation; D012189:Retrospective Studies; D012307:Risk Factors; D012501:Saphenous Vein / Q000637:transplantation*; D013927:Thrombosis / Q000209:etiology / Q000503:physiopathology / Q000517:prevention & control; D013997:Time Factors; D016896:Treatment Outcome; D014654:Vascular Patency
chemical_list: D005343:Fibrinolytic Agents; D011138:Polytetrafluoroethylene