Inclusion Criteria:

- Be at least 21 years old

- Have critical limb ischemia

- Have severe blockages in at least one artery in the affected leg as demonstrated by
an angiogram

- Have nonhealing leg ulcers and/ or have severe rest pain secondary to a severely
decreased blood flow

- Agree to participate in follow-up.

Exclusion Criteria:

- Have any evidence of malignant neoplasms (other than non-melanoma skin cancer or in
situ carcinoma) within the last 5 years

- Be pregnant or lactating

- Have a history of alcohol or drug abuse within 3 months of screening

- Have advanced (Rutherford Category 6) critical limb ischemia, characterized by
extensive tissue loss or gangrene

- Have osteomyelitis

- Have undergone successful aortic or lower extremity surgery, angioplasty, or lumbar
sympathectomy within the 2 months preceding screening

- Be a suitable candidate for surgical or endovascular revascularization in the limb in
which treatment is proposed

- Subjects in whom arterial insufficiency in the lower extremity is the result of a
non-atherosclerotic disorder