Different strategies exist in the treatment of chronic long occlusion of the superficial femoral artery. Traditionally, these patients should be treated with bypass. If the great saphenous vein is unavailable, doctor has to choose artificial vessel as graft. Now, the skill of endovascular treatment is developing rapidly, and lots of doctors think most of such patients could be treated with stent. The purpose of this trial is to compare stent and artificial blood vessel bypass in the treatment of long occlusion of the superficial femoral artery. The study hypothesis is that patency rates are comparable and therefore the minimal invasive treatment of stent can be considered in such patients.

This is a multi-center, prospective, randomized, controlled trial to compare the therapeutic effect of stent and artificial blood vessel bypass to chronic long occlusion of the superficial femoral artery. Totally 200 patients will be entered into the trial. The study population will consist of patients with long superficial femoral stenosis and occlusion lesion (≥15 cm), presenting symptomatic ischemia（Rutherford 3-6）. The lesion does not extend beyond the aortoiliac artery or blow-knee popliteal artery, with at least 1 vessel infra-popliteal runoff to the foot.

Trial participants will be randomized to either stent group or artificial blood vessel bypass group.

Patients 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.

This study will be conducted at 3 centers in Beijing, China.

Inclusion Criteria:

• The patients volunteer to join the trial and sign the formal consent.
• The patients are ≥45 year-old and ≤80 year-old.
• The patients suffer from symptomatic leg ischemia with rutherford classification3, 4 , 5 or 6. The presentation is severe intermittent claudication, rest pain, ulcer or gangrene.
• The total length of the femoral and popliteal artery lesion(including ≥75% stenosis and occlusion) are at least 15cm.
• The femoral-popliteal artery has never received bypass or endovascular therapy before.
• No obvious stenosis or occlusion in the aortoiliac artery; or the lesion could be treated simultaneously or has already been cured.
• No obvious stenosis in below-knee popliteal artery; at least 1 vessel infra-popliteal runoff to the foot.
• No surgical contraindications;no infection in operation region.
• No available saphenous vein.

Exclusion Criteria:

• Refuse random treatment.
• Previous operations on the superficial femoral 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.