The purpose of this trial is to find out the appropriate way to treat DM patients with critical limb ischemia. This trial includes two parts. Part I focuses on the treatment of femoral arterial lesion and part II focuses on the treatment of below-knee arterial lesion.

The trial includes two parts and here is part II. This part is a multi-center, prospective, registration study which focuses on the treatment of below-knee arterial lesion. Totally 130 patients will be entered into this part. They should suffer ischemic symptom with Rutherford 3-6 for the occlusion of the below-knee arteries(anterior tibial、posterior tibial or peroneal artery). According to the lesion length, the patients will accept transluminal angioplasty or below-knee arterial bypass. They will be followed up for 3 years. Study examinations will be done at screening, procedure time, 1, 6, 12, 24 and 36 months after procedure.

Inclusion Criteria:

• The patients volunteer to join the trial and sign the formal consent.
• The patients are ≥55 year-old and ≤75 year-old.
• The patients suffer from symptomatic leg ischemia with rutherford classification3, 4 , 5 or 6.
• Obvious stenosis or occlusion in below-knee popliteal artery
• No obvious stenosis or occlusion in the aortoiliac artery; or the lesion could be treated simultaneously or has already been cured.
• No surgical contraindications;no infection in operation region.
• Be diagnosed with DM for at least 1 year.

Exclusion Criteria:

• Refuse random treatment.
• Previous operations on the target artery.
• Acute lower extremity arterial thrombosis.
• Serious major organ failure.
• Allergic to the contrast agent or has contrast nephropathy.
• No clinical compliance or unfit to join the trial