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

J Vasc Surg. 2010 May;51(5 Suppl):5S-17S. doi: 10.1016/j.jvs.2010.01.073.


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.

Publication types

  • Comparative Study
  • Multicenter Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Aged, 80 and over
  • Amputation, Surgical* / statistics & numerical data
  • Angioplasty, Balloon* / adverse effects
  • Angioplasty, Balloon* / mortality
  • Blood Vessel Prosthesis Implantation
  • Constriction, Pathologic
  • Female
  • Humans
  • Ischemia / diagnostic imaging
  • Ischemia / mortality
  • Ischemia / surgery
  • Ischemia / therapy*
  • Lower Extremity / blood supply*
  • Male
  • Middle Aged
  • Peripheral Vascular Diseases / diagnostic imaging*
  • Peripheral Vascular Diseases / mortality
  • Peripheral Vascular Diseases / surgery
  • Peripheral Vascular Diseases / therapy*
  • Proportional Hazards Models
  • Prospective Studies
  • Radiography
  • Reoperation
  • Risk Assessment
  • Risk Factors
  • Saphenous Vein / transplantation
  • Severity of Illness Index
  • Survival Analysis
  • Time Factors
  • Treatment Outcome
  • United Kingdom
  • Vascular Surgical Procedures* / adverse effects
  • Vascular Surgical Procedures* / mortality

Associated data

  • ISRCTN/ISRCTN45398889