Difficulty recruiting subjects.

Mesenchymal stem cells derived from adipose tissue are pluripotent to differentiate into myocytes, adipocytes or others. They have an immunosuppressive activity. Complex perianal fistula is difficult to cure and easy to relapse. Autologous adipose stem cells have shown efficacy and safety on Crohn's fistula in phase 1 study. Based on these results, the investigators would apply autologous adipose stem cells on complex perianal fistula to evaluate their efficacy and safety.

Inclusion Criteria:

• a patient who has complex perianal fistula
• a patient who is negative in pregnancy test
• a patient who has submitted a written consent

Exclusion Criteria:

• a patient who has participated in other clinical studies within 30 days before this clinical trial or has not passed 5 fold period of a half-life of other investigational drugs.
• a patient who has a history of variant Creutzfeldt Jacobs disease or related diseases
• a patient who is allergic to anesthetics, bovine derived proteins or a fibrin glue
• a patient who has an autoimmune disease
• a patient who has infectious diseases such as hepatitis B virus (HBV), hepatitis C virus (HCV) or human immunodeficiency virus (HIV)
• a patient who has sepsis or active tuberculosis
• a patient who is pregnant or breast feeding
• a patient who has inflammatory Bowel disease
• over 2cm in diameter of fistula