Tolerance of Local Administration of Cryopreserved Autologous Stromal Vascular Fraction Combined With Micrograft for the Treatment of Refractory Ano-perineal Fistulas in Crohn's Disease

The ADICROHN-3 study is a prospective, multicenter, open-label cohort study. Its design is supported by the following elements: * The results of the ADICROHN pilot study (EudraCT No. 2013-002602-31) and our 3-year study, which demonstrate an excellent safety profile with a promising efficacy signal. * Data from the literature confirming that cryopreservation of FVS does not compromise the clonogenic and differentiation potential of mesenchymal progenitors, nor its regenerative effect. * The ongoing ADICROHN-2 study (PHRC N 2019; EudraCT No. 2019-001948-21) confirming the feasibility of patient recruitment, mastery of the therapeutic approach, and the absence of adverse events related to the experimental treatment. * The opportunity for a second FVS injection for patients initially treated but who did not respond to the treatment. * The opportunity for a first FVS injection in patients in the placebo arm, thereby providing access to an innovative therapy available to patients included in this trial who are untreated and remain refractory to standard care. To avoid compromising the results of the ongoing ADICROHN-2 study, enrolled patients will remain blinded to the treatment arm to which they belonged in the ADICROHN-2 study.