• Primary target patency at 12 months. The “target” is the index stenotic lesion(s). Primary patency is defined as <50% residual stenosis by duplex (color-flow Doppler) scan analysis, with antegrade flow to the target vessel.
  

• Ankle Brachial Index (ABI) improvement by ≥0.15 at 3, 6 and 12 months compared to baseline
  
• Change in Walking Impairment Questionnaire (WIQ) functional status scores from baseline at 3, 6 and 12 months
  
• Complications: defined as adverse events (AEs) or serious adverse events (SAEs). Complications may or may not be device related
  
• Cost to patient and hospital: Including operating room times and duration of hospitalization.
  

Peripheral arterial disease affects more than 12 million Americans, and its incidence is growing annually. The male/female ratio of patients with claudication is just under 2/1. The arteries involved by atherosclerosis involve the arteries to the thigh and leg. These include the femoral and popliteal arteries. Fifty percent of people with femoral-popliteal PVD are symptomatic. Symptoms are typically related to exertional fatigue of thigh and calf muscles. These symptoms, referred to as claudication, seldom represent a life or even limb-threatening process. They do, however, result in significantly decreased productivity and an often devastating quality of life.

Traditional interventions for lower extremity claudication include technologies invented in the first half of the 20th century including surgical bypass; and those invented in the second half of the twentieth century, including balloon angioplasty and stenting. These interventions have substantial shortcomings. It is, however, relevant to note that endovascular (aka endoluminal or endovascular surgery) is becoming increasingly popular and gaining wide-spread support from vascular interventionalist societies wordwide.

The main shortcomings of angioplasty and stenting is the resultant inflammatory response. The mechanical injury to blood vessels is followed by a complex repair response comprising intimal vascular smooth muscle cell (VSMC) hyperplasia, vessel wall scarring and shrinkage of the vascular lumen, often resulting in reduced blood flow and subsequent muscle (or end organ) ischemia. Rodent, rabbit and large animal models have provided valuable insights into the pathophysiology of these responses.

The devices utilized in this protocol are both FDA approved for the procedures described in the protocol. The devices include the Silverhawk™ System (FoxHollow Technologies, Redwood City, CA) and the PolarCath™ Peripheral Dilatation System, Boston Scientific, Natick, Massachusetts). Hereafter both products will be referred to as the “Devices.”

Inclusion Criteria:

• The subject must give written informed consent and possess decision making capacity free of sedative or hypnotic agents.
• Age 18 years or older
• Candidate for angiography with intent-to-treat as determined by the Principle Investigator
• On angiography, ipsilateral to a symptomatic limb, a stenotic or occluded de novo or restenotic lesion in the common femoral artery, superficial femoral artery or above the knee popliteal artery measuring no longer than 10 cm (the upper limit of treatment in Cryoplasty pre-marketing)
• On angiography Lesion stenoses between 50% and 100% (inclusive)
• At least one runoff vessel
• Available for follow-up assessments

Exclusion Criteria:

• Contraindication to systemic anticoagulation e.g. history of documented hemorrhage requiring treatment within the past 30 days; history of a hereditary bleeding disorder or known bleeding diathesis; major surgery or trauma, open chest massage, ocular surgery or hemorrhagic retinopathy within the past 30 days; puncture at a non-compressible site within 48 hours prior to planned procedure; history of stroke, intracranial hemorrhage, or central nervous system structural abnormalities within the past 3 months
• History of endovascular surgery procedure or open vascular surgery on the index limb within the last 30 days
• History of significant acute or chronic kidney disease that would preclude contrast angiography
• Known allergy to contrast agents
• History of heparin-induced thrombocytopenia (HIT)
• Participation in any study of an investigational device, medication, biologic, or other agent within 30 days prior to randomization
• Any thrombolytic therapy within 30 days of randomization
• Pregnancy, lactation, or possession of any child bearing potential without evidence of surgical infertility or passage of 12 months since the last day of the subject’s last menstrual period.
• Target lesion involving a dacron prosthesis or a prosthetic of unknown material
• Target lesion extending into the orifice of the profunda femoris artery
• Prisoner status
• Any other subject feature that in the opinion of the investigator should preclude study participation