Umbilical Cord Mesenchymal Stem Cells Injection for Peripheral Arterial Disease

Inclusion Criteria: 1. Age of 18-75 years 2. Patients confirmed diagnosed peripheral vascular disease , ankle-brachial index \< 0.9 3. Poor distal arterial outflow tract 4. Patient had at least 3 months conservative treatment ,which resulted in little or no improvement 5. Poor physical condition can not tolerate surgery 6. Patients are willing to participate in the study and sign the informed consent. Exclusion Criteria: 1. Renal function damage (over 2 X upper normal range) Liver function damage (over 3 X upper normal range ) 2. Severe or acute organ damage 3. Presence of malignancy 4. Pregnancy or lactating patients 5. HIV positive 6. ABI≧0.9 7. A history of severe allergies related cell therapy 8. Conservative treatment \< 3 months 9. Acute limb ischemia 10. Local obvious infection uncontrolled 11. Alcoholics or drug abusers within a year 12. Severe psychiatric disorder. 13. Patients need surgical treatment 14. Above the ankle gangrene 15. Patients with other factors which were considered not to be suitable to participate in the study by the investigators.