- The conventional group patients receive an intravenous injection of prostaglandin E1 (20 ug per day)until the healing of ulcers or discharged from hospital. In the continuous intra-femoral thrombolysis group, first of all, a ultrasound Doppler examination of vessels including artery and venous of lower limbs were performed. To avoid pulmonary infarction, a filtrator is placed in the inferior vena cava before the thrombolysis process if ultrasound results show venous thrombosis. Then insert a percutaneous artery canal from femoral artery in another lower limb into the distal of popliteal artery as far as possible. After finishing this process, the outside part of this artery canal is fixed at thigh, and the patients must keep in supine position in the bed.Firstly,20 0000 ~ 40 0000 units urokinase is injected via the catheter to diseased foot. Then, continuous infusion urokinase via femoral artery by an artery pump (100 ml 0.9% sodium chloride + 100 0000 unit urokinase at a rate of 4 ml per one hour) for 7 - 10 days. Finally, patients receive an intravenous injection of prostaglandin E1 (20 ug per day)until the healing of ulcers or discharged from hospital.