title: Infrainguinal bypass is associated with lower perioperative mortality than major amputation in high-risk surgical candidates.
abstract: BACKGROUND
  Major amputation is often selected over infrainguinal bypass in patients with severe systemic comorbidities because it is assumed to have lower perioperative risks, yet this assumption is unproven and largely unexamined.
  
  
  METHODS
  The 2005 to 2008 National Surgical Quality Improvement Project (NSQIP) database was used to identify all patients undergoing either infrainguinal bypass or major amputation using procedural codes. Patients with systemic or local infections were excluded. A subset of high-risk patients were then defined as American Society of Anesthesiologists (ASA) class 4 or 5, or ASA class 3 with renal failure, dyspnea at rest, ventilator dependence, recent congestive heart failure, or recent myocardial infarct. Propensity score matching was used to obtain two high-risk patient groups matched for preoperative characteristics.
  
  
  RESULTS
  No significant differences in demographic, preoperative, or anesthetic variables were found between the matched, high-risk amputation or bypass groups (792 and 780 patients, respectively). Bypass was associated with a lower 30-day postoperative mortality than amputation (6.54% vs 9.97%; P = .0147). Amputation was associated with higher rates of pulmonary embolism (0.9% vs 0% for amputation vs bypass groups, respectively; P = .009) and urinary tract infection (5.2% vs 2.7%; P = .01), while bypass was associated with higher rates of return to the operating room (14.1% vs 27.6%; P < .001) and a trend toward higher postoperative transfusion requirements (0.9% vs 2.1%; P = .054). The postoperative time to discharge did not differ between the two groups.
  
  
  CONCLUSIONS
  The decision to perform an infrainguinal bypass or amputation should depend on well-established predictors of graft patency and functional success rather than presumptions about different perioperative risks between the two procedures.
authors.affiliation: Division of Vascular and Endovascular Surgery, Department of Surgery, Brigham and Women's Hospital, Boston, MA 02215, USA.
authors.forename: Neal R
authors.initials: NR
authors.lastname: Barshes
authors.forename: Matthew T
authors.initials: MT
authors.lastname: Menard
authors.forename: Louis L
authors.initials: LL
authors.lastname: Nguyen
authors.forename: Richard
authors.initials: R
authors.lastname: Bafford
authors.forename: C Keith
authors.initials: CK
authors.lastname: Ozaki
authors.forename: Michael
authors.initials: M
authors.lastname: Belkin
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000671:Amputation, Surgical / Q000009:adverse effects / Q000401:mortality*; D016009:Chi-Square Distribution; D015897:Comorbidity; D019992:Databases as Topic; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D018579:Patient Selection; D058729:Peripheral Arterial Disease / Q000401:mortality / Q000601:surgery*; D057216:Propensity Score; D012086:Reoperation; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D013997:Time Factors; D016896:Treatment Outcome; D014481:United States / Q000453:epidemiology; D014656:Vascular Surgical Procedures / Q000009:adverse effects / Q000401:mortality*