ATHERO: Advanced Technology Halting Early Re-Stenosis and Occlusion

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