title: Bypass versus Angioplasty in Severe Ischaemia of the Leg (BASIL) trial: An intention-to-treat analysis of amputation-free and overall survival in patients randomized to a bypass surgery-first or a balloon angioplasty-first revascularization strategy.
abstract: BACKGROUND
  A 2005 interim analysis of the Bypass versus Angioplasty in Severe Ischaemia of the Leg (BASIL) trial showed that in patients with severe lower limb ischemia (SLI; rest pain, ulceration, gangrene) due to infrainguinal disease, bypass surgery (BSX)-first and balloon angioplasty (BAP)-first revascularization strategies led to similar short-term clinical outcomes, although BSX was about one-third more expensive and morbidity was higher. We have monitored patients for a further 2.5 years and now report a final intention-to-treat (ITT) analysis of amputation-free survival (AFS) and overall survival (OS).
  
  
  METHODS
  Of 452 enrolled patients in 27 United Kingdom hospitals, 228 were randomized to a BSX-first and 224 to a BAP-first revascularization strategy. All patients were monitored for 3 years and more than half for >5 years.
  
  
  RESULTS
  At the end of follow-up, 250 patients were dead (56%), 168 (38%) were alive without amputation, and 30 (7%) were alive with amputation. Four were lost to follow-up. AFS and OS did not differ between randomized treatments during the follow-up. For those patients surviving 2 years from randomization, however, BSX-first revascularization was associated with a reduced hazard ratio (HR) for subsequent AFS of 0.85 (95% confidence interval [CI], 0.5-1.07; P = .108) and for subsequent OS of 0.61 (95% CI, 0.50-0.75; P = .009) in an adjusted, time-dependent Cox proportional hazards model. For those patients who survived for 2 years after randomization, initial randomization to a BSX-first revascularization strategy was associated with an increase in subsequent restricted mean overall survival of 7.3 months (95% CI, 1.2-13.4 months, P = .02) and an increase in restricted mean AFS of 5.9 months (95% CI, 0.2-12.0 months, P = .06) during the subsequent mean follow-up of 3.1 years (range, 1-5.7 years).
  
  
  CONCLUSIONS
  Overall, there was no significant difference in AFS or OS between the two strategies. However, for those patients who survived for at least 2 years after randomization, a BSX-first revascularization strategy was associated with a significant increase in subsequent OS and a trend towards improved AFS.
authors.affiliation: Department of Vascular Surgery, University of Birmingham, Heart of England NHS Foundation Trust, Solihull Hospital, Lode Lane, Birmingham, UK. Andrew.Bradbury@btinternet.com
authors.forename: Andrew W
authors.initials: AW
authors.lastname: Bradbury
authors.forename: Donald J
authors.initials: DJ
authors.lastname: Adam
authors.forename: Jocelyn
authors.initials: J
authors.lastname: Bell
authors.forename: John F
authors.initials: JF
authors.lastname: Forbes
authors.forename: F Gerry R
authors.initials: FG
authors.lastname: Fowkes
authors.forename: Ian
authors.initials: I
authors.lastname: Gillespie
authors.forename: Charles Vaughan
authors.initials: CV
authors.lastname: Ruckley
authors.forename: Gillian M
authors.initials: GM
authors.lastname: Raab
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000671:Amputation, Surgical / Q000706:statistics & numerical data; D000800:Angioplasty, Balloon / Q000009:adverse effects / Q000401:mortality; D019917:Blood Vessel Prosthesis Implantation; D003251:Constriction, Pathologic; D005260:Female; D006801:Humans; D007511:Ischemia / Q000000981:diagnostic imaging / Q000401:mortality / Q000601:surgery / Q000628:therapy*; D035002:Lower Extremity / Q000098:blood supply*; D008297:Male; D008875:Middle Aged; D016491:Peripheral Vascular Diseases / Q000000981:diagnostic imaging* / Q000401:mortality / Q000601:surgery / Q000628:therapy*; D016016:Proportional Hazards Models; D011446:Prospective Studies; D011859:Radiography; D012086:Reoperation; D018570:Risk Assessment; D012307:Risk Factors; D012501:Saphenous Vein / Q000637:transplantation; D012720:Severity of Illness Index; D016019:Survival Analysis; D013997:Time Factors; D016896:Treatment Outcome; D006113:United Kingdom; D014656:Vascular Surgical Procedures / Q000009:adverse effects / Q000401:mortality