Background: Mesenchymal cell therapy is promising for the treatment of perianal Crohn's fistulas refractory to conventional therapy. Autologous adipose-derived stromal vascular fraction (ADSVF) is recognized as an easily accessible source of cells with angiogenic, anti-inflammatory, immunomodulatory and regenerative properties. ADICROHN pilot study is based on the innovative hypothesis that combined action of ADSVF associated with trophic charasteristics of microfat graft could be beneficial to Crohn patients with refractory perianal fistulas.
Methods: This is a prospective, open, non-comparative, single center, phase I-II clinical trial. Eligible patients are aged >18 years and diagnosed with complex perianal fistula associated with Crohn's disease at least for 6 months with controlled luminal disease (CDAI<220). Fistula(s) had to be refractory to conventional treatment. It was planned to enroll 10 patients. Patients are first subjected to an exam under anaesthesia with drainage by seton placement if indicated, followed at least one week later on the same day by adipose tissue extraction, ADSVF and microfat preparation then injected into the fistula. Patients are monitored at baseline and at 1, 2, 6, 12, 16 and 48 weeks after injection for safety and efficacy analysis. Safety analysis includes at every visits clinical assessment of adverse events. Efficacy analysis includes at every visit clinical evaluation of fistula closure, evaluation of disease activity by PDAI/CDAI scores, and assesment of quality of life by SIBDQ. Fistula closure is also evaluated via radiological assessment with MRI (confirmation of absence of collections >2 cm of the treated perianal fistula) at week 12 and 48.
Results: Since October 2015, 9 patients were treated by this innovative local treatment (among 10 cc of microfat and about 30 millions of ADSVF viable cells subsequently injected into the soft tissue around the fistulas). No serious adverse events have been described. The only side effect were moderate pain on lipoaspiration site. Preliminary efficacy datas at week 12 for the first 7 treated patients showed 71% of response and 28% of complete healing, significant reduction of discharge (p<0.001), significant reduction of severity of perianal disease (p=0.045) and significant improvement of quality of life (p=0.039).
Conclusions: This first study evaluating co-local administration of ADSVF in association with fat graft appears to be a simple, safe and efficient surgical regenerative therapy for perianal Crohn's fistula refractory to conventional therapy.
ClinicalTrials.gov NCT02520843, Eudract: 2013-002602-31.