Study of Autologous Bone Marrow Concentrate for the Treatment of Critical Limb Ischemia (CLI)

Inclusion Criteria: * Diagnosis of Critical Limb Ischemia per protocol (see diagnostic criteria #2) with regard to the study limb. Existence of a PAOD with clinical presentation corresponding to Rutherford Category 4 or Category 5 as defined in the reporting standards adopted by the Society of Vascular Surgeons (table 1) * Patient meets at least one of the following diagnostic criteria in the study limb: * Ankle artery occlusion pressure absolute \<50 mmHg or ABI \<0.4 * Toe artery occlusive pressure \< 40mm Hg or TBI (\<0.4) * TcPO2 \<20 mmHg lying down breathing room air. * There is no reasonable open surgical or endovascular revascularization option as determined by the treating vascular specialist. Factors that may contribute to the determination of inoperability may include: * Anatomical considerations * No outflow targets * No appropriate conduit (i.e. vein for bypass) * Long segment occlusions or calcified lesions that predict poor outcome with endovascular approaches. * High risk medical conditions * Unstable cardiac disease. * Renal insufficiency * History of prior failed revascularization attempts * The patient's unsuitability must be confirmed by 2 qualified physicians. * The attending vascular surgeon will provide the primary assessment. * The confirmatory opinion must come from a fully licensed physician. (not a resident) * If anatomical considerations are invoked, the second physician may be a vascular surgeon, interventional radiologist, cardiologist, or vascular medicine specialist. * If medical co-morbidity is deemed the high risk aspect, then the confirmatory opinion may be obtained from an internist, family physician, cardiologist, vascular medicine, nephrologists, or vascular surgeon. * Age \>18 years and ability to understand the planned treatment * Subject has read and signed the IRB approved Informed Consent form * Patients for whom the following medication(s) is prescribed must have a one month stable baseline of appropriate/maximally tolerated therapy prior to enrollment: Plavix/asprin therapy, anticoagulation therapy, cholesterol lowering agent, and or blood pressure medication * Hematocrit ≥ 28.0%, White Blood Cell count ≤ 14,000, Platelet count ≥ 50,000, Creatinine ≤ 2.0 mg / dL, INR ≤ 1.6 unless on Coumadin, or PTT \<1.5 x control (to avoid bleeding complications) Patients on Coumadin will be corrected prior to the procedure and must have an INR\<1.6 at the time of randomization/surgery. Exclusion Criteria: * Life expectancy \<6 months due to concomitant illnesses * History of bone marrow diseases (especially NHL, MDS) that prohibit transplantation * Terminal renal failure with existing dependence on dialysis * Known active malignancy or results outside of normal limits from the following tests: PAP, Chest X-ray, PSA, Mammogram, Hemoccult unless follow-up studies reveal patient to be cancer free.. * Poorly controlled diabetes mellitus (HgbA1C\>10%) * Medical risk that precludes anesthesia (conscious sedation), or ASA Class 5 * Life-threatening complications of the ischemia necessitating immediate amputation * Uncorrected iliac artery occlusion on index side * No Doppler signal in the foot (ABI =0) * Extensive necrosis of the index limb or other conditions that make amputation inevitable (Rutherford Category 6) * Active clinical infection being treated by antibiotics within one week of enrollment * Treatment with immunosuppressant drugs (including Prednisone \> 5 mg per day). * Female who is pregnant or nursing, or of child bearing potential and is not using a reliable birth control method. * Underwent a major open cardiovascular surgical procedure (carotid endarterectomy, arterial aneurysm or bypass surgery, or coronary artery bypass surgery) or a myocardial infarction within the 3 months prior to randomization * Cerebrovascular accident within 6 months prior to randomization.