Evaluation the Side Effects of Repeated Bone Marrow Derived Mono Nuclear Stem Cells Transplantation in Patients With Lower Limb Ischemic Ulcer

Critical limb ischemia (CLI) results from severe occlusive disease that impairs distal limb perfusion to the point where oxygen delivery is no longer adequate to meet the metabolic needs of the tissue, even under resting conditions. The limits of peripheral artery disease (PAD) compensatory mechanisms, such as distal vasodilatation and collateral formation, have been exceeded at this point. PAD is a widespread disease, affecting up to 15% of all adults older than 55 years. Formation of true new blood vessels, or angiogenesis, and development of collateral vessels from preexisting blood vessels, or arteriogenesis, is important in the pathophysiology of vascular disease. By stimulating these processes the investigators might be able to provide an alternative treatment strategy for patients with lower limb ischemia. In response to tissue injury and remodeling, neovascularization usually occurs via the proliferation and migration of progenitor endothelial cells (EPC) from preexisting vasculature. Indeed, recent studies have shown that bone-marrow mononuclear cell (BM-MNC) implantation increases collateral vessel formation in patients with limb ischemia. So the investigators determine to evaluate the efficacy of repeated MNC transplantation in patients with ischemic lower limb.