BASIL trial bypass benefit debated

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At the ESVS meeting in September 2008, Professor Andrew Bradbury, Birmingham, UK, presented an update on the UK-based, HTA-funded Bypass versus Angioplasty in Severe Limb Ischaemia of the Leg (BASIL) trial.

The BASIL trial was designed to investigate whether, in patients with severe limb ischaemia (rest pain, tissue loss) due to infra-inguinal disease, bypass surgery or balloon angioplasty are associated with a better outcome in terms of amputation-free survival, all cause mortality, a range of secondary clinical endpoints, health-related quality of life and hospital costs.

Since the interim results were published in the Lancet in 2005 patients have been followed for a further 2.5 years; 54% of patients have now completed more than five years follow-up. Although the latest analysis has shown no significant difference in amputation-free survival between the two groups, Bradbury explained that "in patients who survive two years after intervention, surgery was associated with a significant 7.3 month improvement in subsequent all cause mortality at an additional non-significant hospital cost of circa £3,500 over the first three years."

Commenting on the results, Bradbury asked ‘Why might surgery be better in the longer term?’ One explanation, he said, is that revascularisation with surgery appears to be more complete and durable than with angioplasty. In addition, patients who had surgery were less likely to require further intervention, so avoiding the dangers of being back in hospital. A third reason may be aftercare. "Most of the patients who underwent bypass surgery were put under some kind of graft surveillance programme, and also there is a suggestion that these patients have better medical aftercare," Bradbury said.

In conclusion, the BASIL trial strongly suggests that angioplasty should be considered first line treatment for high-risk patients (specifically those with a predicted survival of less than two years) and for patients with no usable veins (the BASIL trial data relates largely to vein [75%] rather than prosthetic grafts). This is because, in the short term (up to one or two years), angioplasty is less morbid and less expensive and such patients will not live to enjoy the longer-term benefits of surgery. However, for all other patients (about 75% of the BASIL cohort) Bradbury recommends surgery as first line treatment. "What we really need is a predictive tool to try to determine which patients will live to two years," he said, adding that such a tool is currently being developed from the BASIL trial cohort to aid future decision-making.