One fourth of patients with peripheral artery disease (PAD) of the lower extremities have severe symptomatic disease and 1-2% have critical limb ischemia (CLI). In patients with CLI, the risk of limb amputation at 1 year is 50%. In addition, patients with CLI often have rest pain, non-healing ulcers and severe limitations of ambulation. Revascularization procedures, including bypass surgery, percutaneous transluminal angioplasty and angioplasty with stenting, are currently the only treatment options. However, many patients are not eligible for a revascularization procedure due to small vessel disease or coexisting medical problems. Moreover, restenosis rates are high.~There is currently no effective non-invasive treatment for critical limb ischemia. We hypothesize that mobilization of angiogenic cells into the blood by granulocyte colony stimulating factor (G-CSF) may stimulate angiogenesis in areas of ischemia and result in a sustained improvement in blood flow in patients with severe PAD.
This study is designed to test the use of G-CSF in peripheral vascular disease. The investigators hypothesize that mobilization of angiogenic cells into the blood by granulocyte colony stimulating factor (G-CSF) may stimulate the formation of new blood vessels and result in a sustained improvement in blood flow in patients with severe peripheral arterial disease.