The proceed subject with two purposes: Study on clinical characteristics of lower extemity arterial disease with infrapopliteal lesions. Evaluate mid-term outcomes and factors influencing clinical outcomes of infrapopliteal angioplasty in patient with lower extremity arterial disease. | Abstract of medical PHD thesis: The clinical characteristics andefficacy ofinfrapopliteal percutaneous transluminal angioplasty in patient with lower extremity arterial disease