Effectiveness of autologous emulsified stromal vascular fraction tissue injection for the treatment of complex perianal fistulas in inflammatory bowel diseases patients: a pilot study.

Complex fistulizing perianal disease is a disabling manifestation of inflammatory bowel disease (IBD), seriously compromising patients 'quality of life'. The success rate of available treatments is quite low, and nearly half of the patients will develop chronically active fistulas or experience fistula recurrence. Mesenchymal stem cell therapy has shown interesting results, but the complexity and the cost of production limit its widespread use. This study aims to report the results of the innovative use of autologous emulsified adipose-derived stromal vascular fraction tissue for treating complex fistulizing perianal disease. From March 2021 to March 2022, 10 patients underwent a two-step procedure: (1) examination under anaesthesia, with loose seton drainage and 4 weeks later and (2) curettage of the fistulous tract, internal fistula closure and an injection of autologous emulsified adipose-derived stromal vascular fraction tissue harvested from the subcutaneous layer of the patient's hip. Clinical and radiological (through magnetic resonance imaging) healing were assessed at 6 months. We included five patients affected by Crohn's disease, three by ulcerative colitis and two by indeterminate colitis. All patients were on concomitant biological therapy (50% on Infliximab). One patient required a re-treatment for a relapse and two different fistulas were separately treated in another one. Out of 12 total procedures performed, clinical healing was achieved in 10 cases (83%), while radiological healing in 6 patients (50%). No adverse events were recorded. Autologous emulsified adipose-derived stromal vascular fraction tissue can represent an effective, safe and cheap add-on therapy for patients with complex perianal fistulas in IBDs.