Autologous Stem Cells Derived From Lipoaspirates for the Non-Surgical Treatment of Complex Perianal Fistula

Inclusion Criteria: Patients of both sexes older than 18 years of age. Patients with a complex perianal fistula pathology which we define as the subjects that fulfil some of the following conditions: No palpation of the fistula tract beneath the perianal skin. A tract that is parallel to the rectum on exploration with a stylet. Associated faecal incontinence. Risk factors of anal incontinence. At least one previous operation for a fistulous disorder. Suprasphincteric trajectories Rectovaginal fistula Prior diagnosis of Crohn's disease. Patients from whom written informed consent has been obtained for them to participate in the study prior to performing any procedure described in the study. Patients that have already been subjected to a colonoscopy within a period of up to 6 months prior to the study. Exclusion Criteria: Patients that are extremely thin who should not be subjected to liposuction. Known allergy to local anaesthetics or to bovine proteins History of neoplasia in the past 5 years. Patients with a diagnosis of active Tuberculosis at the moment of inclusion. Patients with prior positive markers for any of the following pathogens: Hepatitis B and C, HIV-1 or HIV-2. Any other medical condition that in the judgement of the investigator could interfere with their optimal participation in the study or produce a significant risk to the patient. Patients that have participated in another study in the 30 days prior to this one or that have planned to participate simultaneously in another study. Patients that have not given their informed consent to participate in this study. Psychiatric disorder or other factors that in the judgement of the investigator could complicate the participation of the patient in the study. Breast feeding, gestation or intention to become pregnant up to 6 months after finalising their participation in the study, or that are not using adequate methods of contraception during the same period.