P356 Czech experience with treatment of Crohn′s disease perianal fistulas by allogenic mesenchymal stem cell

Abstract

Abstract Background Perianal complex fistulas in Crohn′s disease (CD) are difficult to treat by both surgical and conservative methods. Administration of allogenic, adipose-derived mesenchymal stem cells (darvadstrocel) was studied in a prospective randomised trial (PRS) with a success rate of more than, 50%. The aim of our study was prospectively evaluate results of commercial treatment of perianal fistulas in CD patients by darvadstrocel in Czech Republic. Methods We prospectively followed, 42 consecutive patients treated commercially by darvadstrocel since August, 2019 till August, 2021. Perianal CD activity index (PDAI) was recorded for all patients as well as well as AGA clinical fistula assesment. Complete healing was considered as: no secretion from the external opening, no infiltration perianally, no pain; treatment failure: clear perianal secretion, painful infiltration and / or the need for surgery; partial response: anamnestic mild secretion from one external opening, infiltration around the fistula without pain and without the need for surgical intervention. Results 42 prospectively monitored patients (17M /, 25F), average age, 42 years (range;, 21–70 years) underwent darvastrodstrocel treatment in, 2 Czech mesenchymal stem cell therapy centers (39 pp in NH Hospital, 3 in ISCARE center). Patients suffered from intestinal CD for an average of, 15.6 years (3–34 years), perianal CD for, 8.9 years (2–23 years) and underwent an average of, 7.5(3–24) minor perianal surgeries before the treatment., 38% (16) of patients had anorectal stenosis at the time of the treatment. Patients were treated on average, 25 months (6–84) by stable immunosuppressive and/or biologic therapy. Locally, it was complex fistulas, mostly high trans-sphincteric with, 1–3 external openings (EO) (78.6%;, 33 pp had, 1 EO) and with, 1–2 internal openings (IO) (14.3%;, 6 pp had, 2 IO). Patients were monitored for an average of, 10.5 months (range;, 4–26 months). Complete healing occurred in, 76% patients (32), partial response in, 11.9% (5pp) and treatment failure was in, 5 patients (11.9%). PDAI before MSC surgery was on average, 9.7 (3–13), 3 months after surgery, 3.2 (0–13) and, 6 months after surgery, 2.6 (0–13) in patients who have healed or healed partially. Conclusion The treatment was more successful in real life than in PRS, which may be due to the relatively short follow-up period. Another reason for better outcome could be proper selection of patients with long term stable conservative treatment, which demonstrates stable CD. In our conditions, this treatment is similarly effective as eradication of the fistula using AF, but it can also be used in difficult conditions such as anorectal stenosis or chronic changes in the rectal mucosa.