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

Serclova, Z.(1);Lengálová, M.(1);Zusková, P.(1);Tremerová, A.(1);Drvostepova, L.(1);

(1)NH Hospital, Surgical Department, Horovice, Czech Republic;

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.