Validation of BASIL-2 among patients undergoing primary bypass or angioplasty with or without stenting for chronic limb-threatening ischemia.

Objective: BASIL-2 demonstrated the superiority of an endovascular-first approach in patients with chronic limb-threatening ischemia (CLTI) for the primary endpoint of amputation-free survival (AFS); however, the generalizability of these data are unknown. Thus, we aimed to externally validate these findings by comparing open surgical bypass (BPG) to angioplasty ± stenting (PTA/S), using the BASIL-2 inclusion and randomization criteria.

Methods: All patients undergoing a first-time lower extremity infrapopliteal revascularization for CLTI at our institution from 2005 to 2022 were retrospectively reviewed. To approximate BASIL-2, one-to-one propensity matching was performed. The primary outcome was AFS; secondary outcomes included perioperative complications, major reintervention, major amputation, and major adverse limb events (MALE). A sensitivity analysis was performed assessing the same PTA/S cohort vs BPG with only single-segment great saphenous vein (ssGSV) conduits. Outcomes in the matched cohorts were evaluated using χ², Kaplan-Meier, and Cox regression analyses.

Results: Of 1184 limbs undergoing a first-time infrapopliteal intervention for CLTI between 2005 and 2022, 490 underwent BPG, and 694 underwent PTA/S. After matching, 620 patients (310 BPG and 310 PTA/S) fit our criteria, with no baseline differences noted between groups. Between BPG and PTA/S, the mean age was 71.0 years in both groups, with similar rates of male sex (64% vs 66%), White race (74% vs 75%), coronary artery disease (49% vs 52%), diabetes (75% vs 77%), chronic kidney disease (27% vs 34%), dialysis dependence (17% vs 19%), and smoking history (65% vs 66%). There were no differences in perioperative mortality (4.5% vs 3.9%), stroke (1.0% vs 0.0%), myocardial infarction (2.9% vs 1.3%), or acute kidney injury (12% vs 16%) (all P > .05). BPG, as compared with PTA/S, did not demonstrate any difference in AFS (at 5 years, 36% vs 39%), major reintervention (15% vs 19%), major amputation (24% vs 22%), or MALE (32% vs 36%) (all P > .05). When limiting the BPG group to only ssGSV conduits (n = 267), despite no difference seen in AFS (32% vs 36%), we noted significantly lower rates of major reintervention (12% vs 19%) and MALE (29% vs 36%), demonstrating a 48% and 30% risk reduction, respectively (hazard ratio, 0.52; 95% confidence interval, 0.30-0.89 and 0.69; 95% confidence interval, 0.49-0.98).

Conclusions: Among patients undergoing infrapopliteal revascularization for CLTI, BPG and PTA/S do not differ in regard to AFS, raising concerns regarding the generalizability of BASIL-2. Importantly, infrapopliteal interventions following ssGSV BPG, as compared with PTA/S, do demonstrate significantly lower rates of major reintervention and MALE, reinforcing the benefits of this conduit in patients with CLTI.