DOP76 Comparison of healing of complex perianal Crohn′s disease fistulas by advancement flap and mesenchymal stem cell therapy

Abstract

Abstract Background The combination of surgical approach and biologic treatment is the most successful approach to achieve healing of perianal Crohn′s disease (CD) fistulas. Alongside conventional surgical methods (advancememt flap AF), a new method of fistula closure - allogeneic mesenchymal stem cell (MSC) therapy found its way to clinical practice. Methods The aim of a single centre prospective observational study was to compare the healing results of complex perianal CD fistulas by advancement flap and mesenchymal stem cell therapy (by darvadstrosel). 119 consecutive CD patients with complex fistula (95 with anorectal and 24 anovaginal); treated by MSC-darvastrocel in between 2018 to 3/2022. All patients had a long term loose seton drainage and optimized conventional therapy with luminal remission confirmed by colonoscopy. Complete healing was clinically assessed (no visible external opening or a scar without secretion, no inflammation, no subsequent perianal surgery needed within 3 months post index surgery). Results AF group: Duration of luminal CD was 8,84 years (1-38) and perianal CD 4,74 years (0,5-17). Patients underwent 4,22 (1-23) previous perianal surgeries. The follow up was 11,47 months (0,5-48,9). Conservative therapy (biologics and immunosuppressants) was stable for 23,1 months (1-137). Patients did not suffer from anorectal stenosis or rectal inflammation. MSC group: (60 pp. 36F/24M): Duration of luminal CD was 13 years (2-43 years), of perianal CD 7 years (2-23 years). Number of previous perianal surgeries was 8 (3-25). Conservative therapy was stable for 19 months (1-120). Follow up was 12,5 months (5-34). 38,3% (23) of patients had anorectal stenosis, 38,3% patients underwent advancement flap procedure prior, and 62% suffered from chronic inflammation in rectum. Complete healing was achieved in 86,5 % pts in the AF group and 74.1% of those were healed even with vaginal fistulas. Conclusion There was no significant difference in the healing rate of both methods (p= 0,202). AF procedure could be beneficial in vaginal fistulas, where MSC therapy is contraindicated. MSC therapy is useful in the case of chronic changes of rectal mucosa, anorectal stenosis and the presence of 2 internal openings, where AF procedure is not performable. High success rate in both groups may be conditioned by good preparation of patients (multiple previous drainages) and stable luminal disease (stable conservative treatment).