The objectives of this study are to compare directly conventional balloon angioplasty alone versus. balloon angioplasty with routine stenting - that is, to determine whether angioplasty with self-expanding stent is superior to conventional balloon angioplasty - in the infrapopliteal arterial occlusive lesions of critical limb ischemia patients by collecting and analyzing the cases of each patient group in a prospective multicenter randomized clinical trial, and to clarify main factors affecting mid- and long-term clinical effects of angioplasty with self-expanding stent in the infrapopliteal arteries.

Hypothesis: Balloon PTA followed by routine stenting with self-expanding nitinol stent in critical limb ischemia patients with infrapopliteal arterial occlusive lesions is superior to conventional PTA in the aspect of vascular restenosis rate.

Inclusion Criteria:

• Symptomatic critical limb ischemia (Rutherford 4 - 6)
• Patients with signed informed consent
• Target lesion length < 8 cm by angiographic estimation
• Stenosis of >50% or occlusive atherosclerotic lesion of the ipsilateral infrapopliteal artery
• Reference vessel diameter should be 2.0-4.5 mm

Exclusion Criteria:

• Patient has a known allergy to heparin, aspirin, or other anticoagulant/antiplatelet therapies or a bleeding diatheses or is unable, or unwilling, to tolerate such therapies
• Patient takes warfarin
• Patient has a history of previous life-threatening contrast media reaction
• Patient is currently enrolled in another investigational device or drug trial
• Patient is currently breast-feeding, is pregnant, or intends to become pregnant
• Patient is mentally ill or retarded
• Acute critical limb ischemia
• Major bleeding history within prior 2 months
• Severe hepatic dysfunction (> 3 times normal reference values)
• Significant leucopenia, neutropenia, thrombocytopenia, anemia, or known bleeding diathesis
• Life expectancy <1 year due to comorbidity
• Reference segment diameter is not suitable for available stent design
• Previously implanted stent(s) or PTA at the same lesion site
• Inflow-limiting arterial lesions left untreated