for people ages 18 years and up (full criteria)
at San Francisco, California and other locations
study started
completion around
Principal Investigator
by Michael Conte
Headshot of Michael Conte
Michael Conte



Single phased global, prospective, multicenter clinical trial designed to demonstrate a superior patency rate and acceptable safety in below the knee arteries with lesions treated with the DES BTK Vascular Stent System vs. percutaneous transluminal angioplasty (PTA).

Official Title

A Randomized Trial Comparing the Drug-Eluting Stent (DES) Below-the-Knee (BTK) Vascular Stent System (DES BTK Vascular Stent System) vs Percutaneous Transluminal Angioplasty (PTA) Treating Infrapopliteal Lesions in Subjects With Critical Limb Ischemia


A global, prospective, multicenter, 2:1 randomized trial evaluating the safety and effectiveness of the DES BTK Vascular Stent System compared to standard percutaneous transluminal angioplasty to treat infrapopliteal artery lesions in subjects with critical limb ischemia(CLI).

Approximately 201 subjects will be randomized/enrolled to support a 2:1 randomization.


Critical Limb Ischemia, Chronic Limb-Threatening Ischemia, Ischemia, Drug Eluting Stent - Below the Knee, DES BTK


You can join if…

Open to people ages 18 years and up

  1. Subject is 18 years or older and has signed and dated the trial informed consent form (ICF)
  2. Subject is willing and able to comply with the trial testing, procedures and follow-up schedule
  3. Subject has chronic, symptomatic lower limb ischemia, determined by Rutherford categories 4 or 5 in the target limb, with wound(s) confined to toes/forefoot
  4. Subject is a male or non-pregnant female. If female of child-bearing potential, and if sexually active must be using, or agree to use, a medically-acceptable method of birth control as confirmed by the investigator

    Intra-procedure Inclusion Criteria:

  5. Stenotic, restenotic or occlusive target lesion(s) located in the tibioperoneal trunk, anterior tibial, posterior tibial and/or peroneal artery(ies).
  6. Target lesion(s) must be at least 4cm above the ankle joint
  7. A single target lesion per vessel, in up to 2 vessels, in a single limb
  8. Degree of stenosis ≥ 70% by visual angiographic assessment
  9. Reference vessel diameter is between 2.5 - 3.25mm for phase A RCT
  10. Total target lesion length (or series of lesion segments) to be treated is ≤ 70 mm for phase A RCT prior to the data monitoring committee's approval for stent overlap. (Note: Lesion segment(s) must be fully covered with one DES BTK stent, if randomized to stent)
  11. Total target lesion length (or series of lesion segments) to be treated is ≤ 140 mm for phase A RCT after the data monitoring committee's approval for stent overlap (Note: Lesion segment(s) must be fully covered with up to two DES BTK stents, if randomized to stent)
  12. Target vessel(s) reconstitute(s) at or above the stenting limit zone (4cm above the ankle joint)
  13. Target lesion(s) is located in an area that may be stented without blocking access to patent main branches

    10. Treatment of all above the knee inflow lesion(s) is successful prior to treatment of

    the target lesion

    11. Guidewire has successfully crossed the target lesion(s)

You CAN'T join if...

  1. Life expectancy ≤ 1year
  2. Stroke ≤ 90 days prior to the procedure date
  3. Prior or planned major amputation in the target limb
  4. Previous surgery in the target vessel(s) (including prior ipsilateral crural bypass)
  5. Previously implanted stent in the target vessel(s)
  6. Failed PTA of target lesion/vessel ≤ 60 days prior to the procedure date
  7. Renal failure as measured by a GFR ≤ 30ml/min per 1.73m2, measured ≤ 30 days prior to the procedure date
  8. Subject has a platelet count ≤ 50 or ≥ 600 X 103/µL ≤ 30 days prior to the procedure date
  9. NYHA class IV heart failure

    10. Subject has symptomatic coronary artery disease (ie, unstable angina) 11. History of myocardial infarction or thrombolysis ≤ 90 days prior to the procedure date 12. Non-atherosclerotic disease resulting in occlusion (eg, embolism, Buerger's disease,


    13. Subject is currently taking Canagliflozin 14. Body Mass Index (BMI) <18 15. Active septicemia or bacteremia 16. Coagulation disorder, including hypercoagulability 17. Contraindication to anticoagulation or antiplatelet therapy 18. Known allergies to stent or stent components 19. Known allergy to contrast media that cannot be adequately pre-medicated prior to the

    interventional procedure

    20. Known hypersensitivity to heparin 21. Subject is on a high dose of steroids or is on immunosuppressive therapy 22. Subject is currently participating, or plans to participate in, another

    investigational trial that may confound the results of this trial (unless written approval is received from the Boston Scientific study team)

    Intra-procedure Exclusion Criteria

  10. Angiographic evidence of intra-arterial acute/subacute thrombus or presence of atheroembolism
  11. Treatment required in > 2 target vessels (Note: a target lesion originating in one vessel and extending into another vessel is considered 1 target vessel)
  12. Treatment requires the use of alternate therapy in the target vessel(s)/lesion(s), (eg, atherectomy, cutting balloon, re-entry devices, laser, radiation therapy)
  13. Aneurysm is present in the target vessel(s)
  14. Extremely calcified lesions


  • UCSF
    San Francisco California 94143 United States
  • New Mexico Heart Institute, PA
    Albuquerque New Mexico 87102 United States

Lead Scientist at UCSF

  • Michael Conte
    Professor, Surgery, School of Medicine. Authored (or co-authored) 309 research publications


in progress, not accepting new patients
Start Date
Completion Date
Boston Scientific Corporation
Phase 3 research study
Study Type
About 201 people participating
Last Updated