Factors Associated With Below-the-Ankle Lesions and Their Impact on Clinical Outcomes Following Revascularization in Chronic Limb-Threatening Ischemia.

BACKGROUND

Below-the-ankle (BTA) disease is increasingly prevalent in chronic limb-threatening ischemia (CLTI), particularly in diabetes and end-stage renal disease, but its determinants and prognostic impact after revascularization remain unclear.

METHODS AND

RESULTS

We retrospectively analyzed 185 CLTI limbs with complete pedal angiography undergoing revascularization at 2 vascular centers between 2002 and 2023. Using the Global Limb Anatomic Staging System (GLASS) inframalleolar/pedal artery descriptor (IPD), limbs were classified as BTA (IPD-P2; n=40) or nonBTA (IPD-P0 or P1; n=145). Logistic regression identified factors associated with BTA. Kaplan-Meier compared limb-based patency (LBP), wound healing, limb salvage, and survival. BTA limbs presented with more severe limb status (WIfI stage 4: 72.5% vs. 41.0%; P=0.001), whereas GLASS stage was similar. On multivariable analysis, nonambulatory status independently predicted BTA disease (adjusted odds ratio 2.65; 95% confidence interval 1.19-5.94; P=0.02). BTA disease was associated with lower 1year primary/secondary LBP (55.6% and 72.4% vs. 75.2% and 86.1%; P=0.004 and P=0.005), 6month wound healing (54.0% vs. 83.2%; P=0.0002), 1year limb salvage (77.3% vs. 97.2%; P<0.0001), and 1year survival rates (67.9% vs. 85.6%; P=0.003).

CONCLUSIONS

Non-ambulatory status was independently associated with advanced BTA disease. Despite similar GLASS stage, BTA involvement predicted worse patency, limb outcomes, and survival, suggesting pedal arterial status reflects systemic disease severity.