Feasibility pilot study of the use of ultra-low dose iodinated contrast agent for endovascular procedures in patients with chronic limb-threatening ischemia and renal impairment: the ULTRA-LOW study

PURPOSE: To evaluate the feasibility and safety of an ultra-low-dose iodinated contrast media (CM) protocol during peripheral endovascular procedures in patients with chronic kidney disease (CKD) and chronic limb-threatening ischemia (CLTI). MATERIALS AND METHODS: , stages 2-4) undergoing infrainguinal revascularization over a 1-year period. The protocol utilized 1:9 or 2:8 CM-to-saline dilutions to minimize iodine exposure. Primary endpoints were technical success (revascularization using ≤ 15 mL CM) and the incidence of Contrast-Associated Acute Kidney Injury (CI-AKI), defined as a 25% increase from baseline or a 0.5 mg/dL increase in absolute sCr value, within 72 h. Secondary endpoints included procedural success, limb salvage, and freedom from clinically driven target lesion revascularization (TLR) at 6 months. RESULTS: Eighteen patients were enrolled, presenting advanced (Rutherford 6: 38.9%; occlusions: 38.8%) and complex infrainguinal disease (both femoropopliteal and infrapopliteal disease 27.7%; occlusions 38.8%). Technical success was 94.5%, with a mean CM volume of 10.3 ± 3.5 mL (range: 5-17 mL). Procedural success was 100%. No cases of CI-AKI occurred; one patient (5.5%) required dialysis 3 months post-procedure due to disease progression. Mean sCr and eGFR significantly improved at 72 h compared to baseline (p < 0.0001). At 6 months, limb salvage was 94.4%, TLR-free rate was 81.3% and survival was 83.3%. CONCLUSION: Ultra-low-dose iodinated CM protocol in complex CLTI endovascular treatment of CKD patients is safe and effective, achieving high technical success without evidence of renal function deterioration. LEVEL OF EVIDENCE: Level 4, Case Series.