A Comparison of Clinical Outcomes Between Primary Bypass and Secondary Bypass After Failed Plain Balloon Angioplasty in the Bypass versus Angioplasty for Severe Ischaemia of the Limb (BASIL) Trial

OBJECTIVE: Chronic limb threatening ischaemia (CLTI) is a growing global health problem. The UK NIHR HTA funded BASIL trial is still the only randomised controlled trial to have compared a "bypass surgery first" with a "plain balloon angioplasty (PBA) first" strategy for the management of CLTI. In patients who were likely to survive for 2 years and had a suitable vein, primary bypass (PB) was associated with better clinical outcomes. Furthermore, PBA was associated with a high technical and clinical failure rate and many went on to have secondary bypass (SB). This study aimed at comparing clinical outcomes following PB and SB in the BASIL trial.

METHODS: Demographic, procedural, and outcome data were obtained from the BASIL case report forms. Outcomes were amputation free survival (AFS), limb salvage (LS), overall survival (OS), and freedom from revascularisation (FFR). The SB cohort comprises patients whose first trial intervention was PBA and who subsequently underwent bypass during follow up. The PB cohort comprises those patients whose first trial intervention was bypass.

RESULTS: The 190 PB and 49 SB patients were well matched except that the SB patients were more likely to be current smokers. At a median of 7 years, PB was associated with better AFS (PB 60% vs. SB 40%; HR 1.58, p = .04), LS (PB 85% vs. SB 73%, p = .06), and OS (PB 68% vs. 51%, p = .06). FFR was equivalent (PB 53% vs. 53%, p = .3).

CONCLUSION: In the BASIL trial, clinical outcomes following PB were significantly better than in patients undergoing SB after failed PBA. Prior to treating patients with CLTI with primary PBA, clinicians should consider that if this should fail, the outcome of attempted subsequent bypass is likely to be significantly worse than if PB were attempted.