title: Efficacy of duplex ultrasound surveillance after infrainguinal vein bypass may be enhanced by identification of characteristics predictive of graft stenosis development.
abstract: OBJECTIVE
  Controversy regarding the efficacy of duplex ultrasound surveillance after infrainguinal vein bypass led to an analysis of patient and bypass graft characteristics predictive for development of graft stenosis and a decision of secondary intervention.
  
  
  METHODS
  Retrospective analysis of a contemporary, consecutive series of 353 clinically successful infrainguinal vein bypasses performed in 329 patients for critical (n = 284; 80%) or noncritical (n = 69; 20%) limb ischemia enrolled in a surveillance program to identify and repair duplex-detected graft stenosis. Variables correlated with graft stenosis and bypass repair included: procedure indication, conduit type (saphenous vs nonsaphenous vein; reversed vs nonreversed orientation), prior bypass graft failure, postoperative ankle-brachial index (ABI) < 0.85, and interpretation of the first duplex surveillance study as "normal" or "abnormal" based on peak systolic velocity (PSV) and velocity ratio (Vr) criteria.
  
  
  RESULTS
  Overall, 126 (36%) of the 353 infrainguinal bypasses had 174 secondary interventions (endovascular, 100; surgery, 74) based on duplex surveillance; resulting in 3-year Kaplan-Meier primary (46%), assisted-primary (80%), and secondary (81%) patency rates. Characteristics predictive of duplex-detected stenosis leading to intervention (PSV: 443 +/- 94 cm/s; Vr: 8.6 +/- 9) were: "abnormal" initial duplex testing indicating moderate (PSV: 180-300 cm/s, Vr: 2-3.5) stenosis (P < .0001), non-single segment saphenous vein conduit (P < .01), warfarin drug therapy (P < .01), and redo bypass grafting (P < .001). Procedure indication, postoperative ABI level, statin drug therapy, and vein conduit orientation were not predictive of graft revision. The natural history of 141 (40%) bypasses with an abnormal first duplex scan differed from "normal" grafts by more frequent (51% vs 24%, P < .001) and earlier (7 months vs 11 months) graft revision for severe stenosis and a lower 3-year assisted primary patency (68% vs 87%; P < .001). In 52 (15%) limbs, the bypass graft failed and 20 (6%) limbs required amputation.
  
  
  CONCLUSIONS
  The efficacy of duplex surveillance after infrainguinal vein bypass may be enhanced by modifying testing protocols, eg, rigorous surveillance for "higher risk" bypasses, based on the initial duplex scan results and other characteristics (warfarin therapy, non- single segment saphenous vein conduit, redo bypass) predictive for stenosis development.
authors.affiliation: Division of Vascular and Endovascular Surgery, University of South Florida College of Medicine, Tampa, Florida, USA.
authors.forename: Chelsey N
authors.initials: CN
authors.lastname: Tinder
authors.forename: Joe P
authors.initials: JP
authors.lastname: Chavanpun
authors.forename: Dennis F
authors.initials: DF
authors.lastname: Bandyk
authors.forename: Paul A
authors.initials: PA
authors.lastname: Armstrong
authors.forename: Martin R
authors.initials: MR
authors.lastname: Back
authors.forename: Brad L
authors.initials: BL
authors.lastname: Johnson
authors.forename: Murray L
authors.initials: ML
authors.lastname: Shames
mesh_terms: D000925:Anticoagulants / Q000009:adverse effects; D005121:Extremities / Q000098:blood supply*; D005260:Female; D006083:Graft Occlusion, Vascular / Q000000981:diagnostic imaging* / Q000209:etiology / Q000503:physiopathology / Q000601:surgery; D006801:Humans; D007511:Ischemia / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D008297:Male; D011182:Postoperative Care; D012086:Reoperation; D012189:Retrospective Studies; D012307:Risk Factors; D012501:Saphenous Vein / Q000637:transplantation*; D013997:Time Factors; D017211:Treatment Failure; D018616:Ultrasonography, Doppler, Duplex; D014654:Vascular Patency; D014656:Vascular Surgical Procedures / Q000009:adverse effects; D014859:Warfarin / Q000009:adverse effects
chemical_list: D000925:Anticoagulants; D014859:Warfarin