PROMISE International

This study will investigate the safety and effectiveness of the LimFlow System for creating an arterio-venous fistula in the below-the-knee vascular system using an endovascular, minimally invasive approach for the treatment of critical limb ischemia in subjects ineligible for conventional endovascular or surgical limb salvage procedures.

Inclusion criteria

• Subject must be > 21 and < 95 years of age
• Clinical diagnosis of symptomatic critical limb ischemia, defined as Rutherford category 5 or 6
• Assessment that no conventional surgical or endovascular treatment is possible
• Proximally, the target in-flow artery at the cross-over point must be treatable with a 3.5 - 4.0 mm stent after pre-treatment (by visual estimate), and be <50% stenosed
• Subject is willing and has adequate support to comply with protocol requirements, including medication regimen and follow-up visits

Exclusion criteria

• Concomitant hepatic insufficiency, deep venous thrombus in target limb, uncorrected coagulation disorders, or current immunodeficiency disorder
• Prior vein stripping surgery and/or vessel harvesting for CABG in the limb intended for study
• Life expectancy less than 12 months
• Patient currently taking coumarin/warfarin which, in the opinion of the attending physician, interferes with the patient's treatment
• Any significant medical condition which, in the attending physician's opinion, may interfere with the patient's optimal treatment
• Patient currently participating in another investigational drug or device study that has not completed the primary endpoint or that clinically interferes with the endpoints of this treatment
• Patient unable to give consent
• Pregnant or breastfeeding women
• Documented myocardial infarction or stroke within previous 90 days
• Patients suffering from renal insufficiency (GFR value less than 30 ml/min/1.73 m²) who are not on hemodialysis
• Patients with vasculitis and/or untreated popliteal aneurysms
• Patients with acute limb ischemia
• Prior peripheral arterial bypass procedure above or below the knee which could inhibit proximal inflow to the stent graft
• Lower extremity venous disease with significant edema in the target limb that may inhibit the procedure and/or jeopardize wound healing, in the investigator's opinion
• Known or suspected systemic or severe infection (e.g., WIfI foot Infection grade of 3)
• Known or suspected allergies or contraindications to stainless steel, nickel, or contrast agent that cannot be adequately pre-treated, or patients who cannot receive anticoagulation or antiplatelet aggregation therapy
• Severe heart failure, which in the opinion of the investigator may compromise subject's ability to safely undergo a percutaneous procedure (e.g., known ejection fraction of < 40%, NYHA Classification III-IV)