Autologous CD34+ Stem Cell Injection for Severe Intermittent Claudication (Leg Pain)

The goal of the study is to determine the safety and possible effectiveness of various doses of autologous (one's own) stem cells, delivered with a needle into the regions of the leg with poor blood flow in patients with blocked leg arteries that results in claudication (pain when walking). Stem cells are primitive cells produced by the bone marrow that can develop into blood cells or other types of cells. In addition to determining whether this new approach is safe, the diagnostic tests may offer preliminary insights into the usefulness of this approach for treating intermittent claudication - the condition where areas in the leg are lacking enough oxygen and blood flow to keep the leg muscle working well, causing pain and cramping upon walking. This study is a double-blind, randomized study to compare CD34-positive stem cells versus a placebo agent (salt water solution known as normal saline). The patient will have a 3:1 chance of their stem cells versus the placebo. Regardless of a patient receiving placebo or treatment, all patients will undergo all of the pre-treatment phases of this study, which includes the stem cell mobilization and apheresis procedure.