Inclusion Criteria:

-Atherosclerotic ischemic peripheral vascular disease with rest pain defined as pain that occurs at night or at rest that involves the foot and is a sign of end stage vascular disease and / or ischemic lower extremity ulcers due to infra-inguinal disease and/or peak walking time of 1 to 6 minutes on two exercise tests separated by 2 weeks on graded treadmill.

Either a or b

1. Ankle brachial index (ABI) < 1.0.

2. Doppler waveforms at posterior tibial artery and dorsalis pedis artery are monophasic with toe pressure < 30 mmHg.

   • A non-surgical candidate for revascularization e.g. prior vascular reconstruction, inability to locate a suitable vein for grafting, diffuse multi- segment disease, or extensive infra-popliteal disease not amenable to a vascular graft.
   • Age > 18 years old.

Exclusion Criteria:

• Popliteal vascular entrapment syndrome
• Lower Extremity infection or infected ulcer
• Hypercoagulable state
• HIV positive
• HBsAg positive
• Uncontrolled arrhythmia, that is, persistence of an arrhythmia despite medical therapy
• Unstable angina
• Thrombocytopenia < 100,000/ul
• Anemia that cannot be transfused to a hemoglobin greater than 10 g/dl
• Leukemia or myelodysplasia
• Allergy to E coli or its products
• Patients with metal in their bodies cannot undergo MRIs (MRA). Therefore, patients with, cochlear implants, or aneurysm clips are not eligible. Coronary artery stents are not a contraindication. Patients with pacemakers are still candidates provided they have normal creatinine (< 1.1 mg/dl) and can receive contrast dye (no allergy) for angiogram instead of MRA.
• Patients who are pregnant
• Poorly controlled diabetes (HbA1c > 6.5)
• Current malignancy, except squamous cell or basal cell skin cancers thought to be easily controlled.
• AST, ALT, or bilirubin more than twice the upper limit of normal.
• WBC < 2.5 / ul.
• Any patient who is actively bleeding, including blood on urine dipstick or fecal occult blood.
• No patient may be re-treated until at least 5 patients have completed 6 months of follow-up with no notable safety findings and evidence of therapeutic efficacy (improved ABI or healing ulcer) occurred at stem cell doses higher than the patient received in this dose escalation study or response occurred in the treated leg and the untreated leg meets eligibility criteria. Re-treated patients must meet eligibility criteria.
• Patients who smoke unless stop smoking at least two weeks before enrollment and agree not to smoke thereafter.