Stem Cells Treatment for Extremely Complex Fistulae (HULPCIR)

Inclusion Criteria: * Signed informed consent * Extremely Complex perianal fistulae * Men and women over 18 years old. Good general state of health according to the findings of the clinical history and the physical examination * Previous failure in at least one closing fistula standard treatment Exclusion Criteria: * Presence of severe proctitis or dominant active luminal disease requiring immediate therapy * Patients with an abscess unless a complete toilet of the area with drainage of the collections and the absence of abscess and other collections is confirmed prior to treatment start * Patients with a history of abuse of alcohol or other addictive substances in the 6 months prior to inclusion * Patients with malignant tumor, except for basal cell or cutaneous squamous cell carcinoma, or patients with a prior history of malignant tumors, unless the neoplastic disease has been in remission for the previous 5 years * Patients with cardiopulmonary disease which, in opinion of the investigator, in unstable or sufficiently serious to exclude the patient from the study. * Patients with any type of medical or psychiatric disease which, in the opinion of the investigator, could be grounds for exclusion from study * Patients with congenital or acquired immunodeficiencies. HIV, HBV, HCV or treponema infection, whether active or latent * Patients who have suffering major surgery or severe trauma in the prior 6 months * Pregnant or breastfeeding women * Patients currently receiving, or having received within 1 month prior to enrollment into this clinical trial, any investigational drug