a prospective single-arm multicenter study of the bare temporary spur stent system for the treatment of vascular lesions located in the infrapopliteal arteries below the knee (deeper reveal)

Conditions: Peripheral Arterial Disease; Critical Limb Ischemia

Summary: this is a prospective, multicenter, single arm study designed to evaluate the safety and efficacy of the temporary bare spur stent system (spur stent system).


Eligibility criteria:
pre-procedure inclusion criteria: 1. subject willing and able to provide informed consent and able to comply with the study protocol and follow up. subjects who are unable to sign due to a physical limitation may have a witness, including a family member, sign on their behalf. 2. life expectancy greater than 1 year in the investigator's opinion. 3. male or non-pregnant female ≥18 years of age at time of consent. 4. subjects must have chronic (greater than 14 days) symptoms of limb ischemia, determined by clinical symptoms of rutherford class 4-5, rest pain (r 4), and/or minor tissue loss (r5), that in the opinion of the investigator are not amenable to conservative medical therapy and require endovascular intervention for alleviation of symptoms and tissue preservation. 5. for subjects with bilateral disease, planned treatment of the contralateral limb must either be performed greater than or equal to 3 days prior to the index procedure or greater than or equal to 7 days following the index procedure. angiographic inclusion criteria: 1. stenotic, restenotic, or occlusive lesions located in the infrapopliteal vessels, with target lesion that can be successfully crossed via the true lumen with a guidewire (no subintimal crossing). 2. iliac, sfa and popliteal inflow lesions can be treated using standard of care during the index procedure or greater than or equal to 3 days prior. note: 1. inflow lesions treated intraprocedure must be treated first, prior to consideration of treatment of infrapopliteal lesions. 2. treatment of in-stent restenosis in inflow treatment is permitted, provided that stents are not fractured or otherwise compromised. 3. distal embolic protection is strongly encouraged in cases where atherectomy is used. 4. inflow lesions must have a healthy vessel segment of greater than 30 mm between the study lesion and the treated segment, defined as less than 50% stenosis without aneurysmal segments. 5. inflow treatment must be successful, prior to treatment of the target lesion, resulting in stenosis less than or equal to 30%, without resulting flow limiting dissection, thrombus, or aneurysm by angiography. 3. target vessel(s) reconstitute(s) at or above the ankle, with the target treated segment ending at least 10 mm above the ankle joint. note: 1. if the anterior tibial or posterior tibial arteries are treated, there must be inline flow to the foot. 2. if the peroneal artery is treated, there must be at least one collateral supplying the foot. 3. in all cases, patent runoff (no lesions with greater than 50% stenosis) must be present via the dorsalis pedis and/or plantar arteries 4. target lesion must be located in the tibial arteries. if vessel sizing remains appropriate, treatment may extend into the distal popliteal (p3) segment. 5. target vessel reference diameter is measured to be between 2.5 to 4.5 mm in diameter assessed by one of the following methods after successful completion of guidewire crossing of the lesion site: 1. intravascular ultrasound (ivus) (primary) 2. visual estimate using angiography (secondary) 6. target lesion length is less than or equal to 210mm in length. tandem lesions that are less than or equal to 4 cm should be treated as one lesion. multiple discrete lesions may be treated provided cumulative length is less than or equal to 210 mm. 7. successful pre-dilatation of the target lesion defined as resulting in stenosis less than or equal to 50% and/or inner lumen diameter greater than or equal to 2.0 mm in diameter, without resulting flow limiting dissection, thrombus, or aneurysm by angiography prior to the insertion of the bare temporary spur stent system. 8. only one limb and one contiguous vessel may be enrolled per subject. if required, a second modality may be used for treatment in the non-target infrapopliteal vessel. note: 1. distal embolic protection is strongly recommended in cases using atherectomy. 2. treatment of the target vessel/lesion may be performed only if treatment of the non-target lesion is successful without resulting flow limiting (type d or greater) dissection, thrombus, or aneurysm by angiography. 3. treatment of non-target lesions must be parallel to, and not contiguous with, the target lesion. 9. if pre-screening with duplex ultrasound, angiography, cta, or mra has been performed less than or equal to 365 days prior to the procedure, intra-procedure angiography of the aorto-iliac vasculature is not required, however, the femoropopliteal inflow must still be imaged using angiography during the index procedure. 10. retrograde access (in the infrapopliteal arteries) is permitted for lesion crossing; however, the bare temporary spur stent system must be deployed from antegrade (above the knee, either ipsilateral or contralateral) access. pre-procedure exclusion criteria: 1. subject unwilling or unlikely to comply with the 1-year duration of the study in the opinion of the investigator. 2. subject is pregnant or planning to become pregnant during the course of the trial. 3. subject has an active systemic infection that is not controlled at the time of the procedure, including septicemia or bacteremia. 4. subject has osteomyelitis proximal to the phalanges. osteomyelitis in the digit(s) of the target foot is permitted. 5. wounds must be confined to the foot below the ankle. heel wounds are excluded. 6. planned major (above the ankle) amputation of the target limb. a planned or previous minor (trans metatarsal amputation or digit amputation) is permitted. 7. recent myocardial infarction or stroke less than 90 days prior to the index procedure. 8. symptomatic acute heart failure nyha class iii or greater. 9. impaired renal function (egfr less than or equal to 25 ml/min) within 30 days of procedure or end stage renal disease on dialysis. 10. inability to tolerate dual antiplatelet and/or anticoagulation therapy. 11. known allergies or sensitivities to heparin, antiplatelet drugs, other anticoagulant therapies which could not be substituted, or an allergy to contrast media that cannot be adequately pre-treated prior to the index procedure. 12. the subject is currently enrolled in another investigational device or drug trial that interferes with the study endpoints. 13. known allergy to nitinol or nickel. 14. bypass surgery of the target vessel(s). prior bypass above the level of the infrapopliteal arteries is permitted. angiographic exclusion criteria 1. target lesion is located within an aneurysm or associated with an aneurysm in the vessel segment either proximal or distal to the target lesion. inflow must also be free of aneurysmal segments. 2. fractured or otherwise compromised stents in the target vessel or inflow vessel. 3. in-stent restenosis in the target vessel. 4. previous treatment of inflow lesions performed less than or equal to 7 days prior to the index procedure. 5. previous treatment of the target vessel less than or equal to 90 days prior to index procedure. 6. angiographic evidence of thrombus within target limb. 7. extremely severe calcification that, in the investigator's opinion, would not be amenable to pta. 8. type d dissections or greater incurred during cto crossing (see appendix i for definitions). 9. significant (greater than or equal to 50%) stenosis of inflow arteries or unsuccessful treatment of inflow lesions. 10. distance from access to lesion is too long for a 135 cm working length of the bare temporary spur stent system catheter.

Keywords: peripheral arterial disease critical limb ischemia infrapopliteal disease