multicentre randomized controlled prospective study aimed at evaluating the efficacy of the infiltration of microfractured adipose tissue in the healing of perianal fistulas not-responding to treatment with biologics, in order to improve the quality of life and significantly reduce the risk of definitive ostomy.

Inclusion Criteria:

• The patient's age is over 18 at the time of surgery.
• The patient suffers from Crohn's disease confirmed by instrumental and histological methods.
• The patient presents with complex perianal fistulising disease refractory to standard treatment (combination of surgical drainage of sepsis and local / systemic administration of anti-TNF-α for at least 1 year)
• The patient received, understood and signed informed consent for active participation in the study.
• The patient is able to understand the conditions of the study and to participate throughout the duration.

Exclusion Criteria:

• Patients with more than 1 internal and 3 external openings.
• Patients with ileus / colo ostomy.
• Patients with anus / rectum-vaginal fistulas.
• Patients with active HIV infections, hepatitis C (HCV), hepatitis B (HBV), tuberculosis.
• Patients with abdominal localization of Crohn's disease who may require general surgery during the study.
• Patients with active oncological or lymphoproliferative diseases from which it was not possible to safely withdraw an adequate quantity of lipoaspirate (at least 60 cc).
• Patients with clinical conditions that may compromise the success of the surgery or the follow-up.
• Pregnant or breastfeeding women.