The objective of this post-market study is to evaluate the safety and effectiveness of the LimFlow System in creating a below-the-knee arterio-venous fistula for venous arterialization in subjects with critical limb ischemia.

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)

Undecided

1 year

PROMISE UK was a post-market study of a CE-marked device and consisted of a single study arm with no direct comparator due to the extreme nature of the alternative other than major amputation. As such, all data reported are descriptive and are not tested in a statistical nature against the known rates of amputation and mortality of no treatment.