Critical limb ischemia (CLI) is a condition caused by blocked arteries leading to low blood flow to the legs, feet, and other extremities. This causes severe pain, skin sores, gangrene, and can also lead to death. Amputation is often needed due to a lack of effective treatment options for CLI. The poor outcomes for patients with CLI have stimulated research efforts to find effective treatments such as autologous cell therapies. A new approach to treatment that is being investigated involves using cells from bone marrow aspirate supplied by HemaCare (bone marrow collected with a needle and syringe).