title: Prior contralateral amputation predicts worse outcomes for lower extremity bypasses performed in the intact limb.
abstract: BACKGROUND
  To date, history of a contralateral amputation as a potential predictor of outcomes after lower extremity bypass (LEB) for critical limb ischemia (CLI) has not been studied. We sought to determine if a prior contralateral lower extremity amputation predicts worse outcomes in patients undergoing LEB in the remaining intact limb.
  
  
  METHODS
  A retrospective analysis of all patients undergoing infrainguinal LEB for CLI between 2003 and 2010 within hospitals comprising the Vascular Study Group of New England was performed. Patients were stratified according to whether or not they had previously undergone a contralateral major or minor amputation before LEB. Primary end points included major amputation and graft occlusion at 1 year postoperatively. Secondary end points included in-hospital major adverse events, discharge status, and mortality at 1 year.
  
  
  RESULTS
  Of 2636 LEB procedures, 228 (8.6%) were performed in the setting of a prior contralateral amputation. Patients with a prior amputation compared to those without were younger (66.5 vs 68.7; P = .034), more like to have congestive heart failure (CHF; 25% vs 16%; P = .002), hypertension (94% vs 85%; P = .015), renal insufficiency (26% vs 14%; P = .0002), and hemodialysis-dependent renal failure (14% vs 6%; P = .0002). They were also more likely to be nursing home residents (8.0% vs 3.6%; P = .036), less likely to ambulate without assistance (41% vs 80%; P < .0002), and more likely to have had a prior ipsilateral bypass (20% vs 12%; P = .0005). These patients experience increased in-hospital major adverse events, including myocardial infarction (MI; 8.9% vs 4.2%; P = .002), CHF (6.1% vs 3.4%; P = .044), deterioration in renal function (9.0% vs 4.7%; P = .006), and respiratory complications (4.2% vs 2.3%; P = .034). They were less likely to be discharged home (52% vs 72%; P < .0001) and less likely to be ambulatory on discharge (25% vs 55%; P < .0001). Although patients with a prior contralateral amputation experienced increased rates of graft occlusion (38% vs 17%; P < .0001) and major amputation (16% vs 7%; P < .0001) at 1 year, there was not a significant difference in mortality (16% vs 10%; P = .160). On multivariable analysis, prior contralateral amputation was an independent predictor of both major amputation (odds ratio, 1.73; confidence interval, 1.06-2.83; P = .027) and graft occlusion (odds ratio, 1.93; confidence interval, 1.39-2.68; P < .0001) at 1 year.
  
  
  CONCLUSIONS
  Patients with prior contralateral amputations who present with CLI in the intact limb represent a high-risk population, even among patients with advanced peripheral arterial disease. When considering LEB in this setting, both physicians and patients should expect increased rates of perioperative adverse events, increased rates of 1-year graft occlusion, and decreased rates of limb salvage, when compared with patients who have not undergone a contralateral amputation.
authors.affiliation: Division of Vascular and Endovascular Surgery, University of Massachusetts Medical School, Worcester, MA 01655, USA. donald.baril@umassmemorial.org
authors.forename: Donald T
authors.initials: DT
authors.lastname: Baril
authors.forename: Philip P
authors.initials: PP
authors.lastname: Goodney
authors.forename: William P
authors.initials: WP
authors.lastname: Robinson
authors.forename: Brian W
authors.initials: BW
authors.lastname: Nolan
authors.forename: David H
authors.initials: DH
authors.lastname: Stone
authors.forename: YouFu
authors.initials: Y
authors.lastname: Li
authors.forename: Jack L
authors.initials: JL
authors.lastname: Cronenwett
authors.forename: Andres
authors.initials: A
authors.lastname: Schanzer
mesh_terms: D000368:Aged; D000671:Amputation, Surgical; D005260:Female; D006083:Graft Occlusion, Vascular / Q000453:epidemiology; D006801:Humans; D007511:Ischemia / Q000601:surgery*; D007866:Leg / Q000098:blood supply*; D008297:Male; D015999:Multivariate Analysis; D011183:Postoperative Complications / Q000453:epidemiology*; D011379:Prognosis; D012189:Retrospective Studies; D016896:Treatment Outcome; D014656:Vascular Surgical Procedures / Q000009:adverse effects