Safety and Efficacy of Adipose-Derived Stem Cells to Treat Complex Perianal Fistulas Patients With Crohn's Disease

Inclusion Criteria: * Signed informed consent * Patients with Crohn's disease diagnosed at least 12 months earlier in accordance with accepted clinical, endoscopic, anatomopathological and/or radiologic criteria * Presence of complex perianal fistula with 3 or fewer fistulous tracts assessed by MRI * Patients with persistent and active complex perianal fistula and non-active luminal Crohn's disease defined by a CDAI ≤ 200. (Complex perianal fistula is defined as a fistula that meets one or more of the following criteria: High fistulas \[high inter-sphincteric, high trans-sphincteric, extra-sphincteric or supra-sphincteric\], presence of 3 or fewer external openings \[tracts\] associated with a complex perianal fistula, or pain/fluctuation * Good general state of health according to the findings of the clinical history and the physical examination * Women of a childbearing age with negative serum or urine pregnancy test (sensitive to 25 IU hCG). Both men and women should use appropriate birth control methods defined by the investigator Exclusion Criteria: * Presence of severe proctitis (prominent friability, spontaneous bleeding, multiple erosions, deep ulcers) or dominant active luminal disease requiring immediate therapy, assessed by rectosigmoidoscopy * Patients with a CDAI ≥201 * 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 * The presence of setons unless removed prior to the study procedure * Presence of \>3 fistulous tracts and/or external openings * Patients with rectal and/or anal stenosis evaluated by rectoscopy or EUA * Patients who have received infliximab or any other anti-TNF agent in the 8 weeks before the cell treatment administration * Patients who have received tacrolimus or cyclosporine in the 4 weeks before the cell treatment administration * Patients with rectovaginal fistula, anal fistula(s), and/or non-perianal enterocutaneous fistula * Patients with HIV, HBV, HCV or treponema infection, whether active or latent * 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 the opinion of the investigator, is 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 the study * Patients with congenital or acquired immunodeficiencies * Patients with abnormal laboratory test findings that contraindicate their inclusion in the study * Patients allergic to local anesthetics or gadolinium (MRI contrast) * MRI is unfeasible, (e.g. due to the presence of pacemakers, hip replacements or severe claustrophobia) * Liposuction with extraction of at least 100 cm3 of fat from the abdominal wall is technically unfeasible or the patient does not consent to the procedure * Patients in need of surgery in the perianal region for reasons other than fistulas at the time of inclusion in the study, or a need for such surgery is foreseen in this region in the 26 weeks after treatment administration. * Patients who have suffered major surgery or severe trauma in the prior 6 months * Pregnant or breastfeeding women * Patients who do not wish to or cannot comply with study procedures * Patients currently receiving, or having received within 1 month prior to enrolment into this clinical trial, any investigational drug * Patients unlikely to comply with study procedures