A Comparison of Clinical Outcomes Following Femoro-Popliteal Bypass or Plain Balloon Angioplasty with Selective Bare Metal Stenting in the Bypass Versus Angioplasty in Severe Ischaemia of the Limb (Basil) Trial

Abstract

Introduction - The Bypass versus Angioplasty for Severe Ischaemia of the Leg (BASIL-1) trial is the only randomised controlled trial (RCT) to have compared a bypass surgery (BS) first with a best endovascular treatment (BET) first revascularisation strategy for the treatment of chronic limb threatening ischaemia (CTLI) due to infra-inguinal disease. BASIL-1 found that, in patients who survived for more than 2 years, BS was associated with better amputation free (AFS) and overall (OS) survival. However, these data included patients undergoing femoro-popliteal (FP) and infra-popliteal (IP) procedures. The aim of the present study is to examine outcomes in the sub-group of BASIL-1 patients who underwent FP BS or plain balloon angioplasty (PBA) +/- bare metal stent (BMS) in order to build equipoise for the BASIL-3 trial which is randomising CLTI patients to FP PBA +/- BMS vs drug coated balloon (DCB) +/- BMS vs primary drug eluting stent (DES). Methods - Outcome data were obtained from prospectively gathered BASIL-1 case record forms. Differences between BS and PBA+/-BMS were compared using the t-test, chi-squared and Wilcoxon rank sum tests according to the distribution of data using SAS v9.4. Results - A total of 311 BASIL-1 patients were studied; 128 undergoing primary SB (89 VB, 39 SynB) and 183 primary PBA+/-BMS. PBA+/-BMS patients were older and more likely to be current smokers, and SB patients were more likely to have chronic obstructive pulmonary disease (COPD). Immediate technical success was significantly better for SB (98% vs. 81%, p<0.0001). Patients undergoing SB had a longer mean index hospital admission (16 vs. 8 days, p=0.0001). However, at 12 months patients in both groups had spent an equivalent mean number of days (n = 17) in hospital. All-cause 30-day mortality was not statistically different between the two groups, PBA+/-BMS patients underwent more re-interventions within the first 30-days (2% vs 7%, p=0.06). There was no significant difference in AFS (HR 1.18, p=0.4), OS (HR 1.14, p=0.5) or LS (HR 1.09, p=0.8) between SB and PBA+/-BMS. However, FF-MALE (HR 1.51, p=0.04) and FF-R (HR=1.68, p=0.02) were significantly better following SB. FF-MALE (71% vs 58% vs 56%, p=0.02) was significantly better following VB. Resolution of rest pain (HR=0.84, p=0.2) and wound healing at 3 years (HR=0.78, p= 0.2) were similar in the two groups. Conclusion - This BASIL subgroup analysis indicates that although amputation rates and overall survival are similar, primary SB, especially VB, resulted in significantly fewer MALE and re-interventions than PBA+/-BMS. So, although an endovascular first revascularisation strategy may be a less resource intensive and morbid option in the short term, this appears unlikely to be the case in the long-term. Present data add further weight to the argument that, where possible, most patients presenting with CLTI due to FP disease should be offered VB as their primary revascularisation procedure where suitable autogenous conduit is available.