Sirolimus-Coated Balloon Angioplasty of Infra-popliteal Lesions for the Treatment of Chronic Limb-Threatening Ischemia: Study Protocol for the Randomized Controlled LIMES Study

PURPOSE: Evidence on efficacy and long-term safety of paclitaxel-coated devices is still conflicting. Therefore, this study aims to assess whether sirolimus-coated balloon angioplasty is safe and effective for the treatment of infra-popliteal occlusions in patients with chronic limb-threatening ischemia (CLTI). STUDY DESIGN: The randomized controlled, single-blinded, multicentre, investigator-initiated study aims to enrol 230 participants with CLTI and infra-popliteal occlusions at up to 25 centres. Patients will be randomized in a 1:1 ratio to either sirolimus-coated balloon angioplasty or to plain old balloon angioplasty (POBA). Bailout stenting in case of flow-limiting dissection or ≥ 50% residual diameter stenosis is permitted. OUTCOME MEASURES: Primary outcome is the Kaplan–Meier estimate of primary patency at 6 months, defined as the absence of target lesion occlusion with restoration of in-line flow to the ankle. Key secondary outcome is non-inferiority in the proportionate occurrence of major adverse limb events and perioperative all-cause death at 30 days. Overall, participants will be followed for 36 months to assess further secondary efficacy and safety outcomes. ASSUMED GAIN OF KNOWLEDGE: If sirolimus-coated balloon angioplasty turns out to be superior to uncoated-balloon angioplasty regarding patency of infra-popliteal lesions without safety signals, it could become a welcome treatment option for patients with CLTI. Trial Registration ClinicalTrial.gov Identifier: NCT04772300, German Clinical Trials Register: DRKS00024629. Level of Evidence Level 2a, randomized controlled trial.