Fistula Plug in Fistulising Ano-Perineal Crohn's Disease: a Randomised Controlled Trial

Background and aims: Anal fistula plug [AFP] is a bioabsorbable bioprosthesis used in ano-perineal fistula treatment. We aimed to assess efficacy and safety of AFP in fistulising ano-perineal Crohn's disease [FAP-CD].

Methods: In a multicentre, open-label, randomised controlled trial we compared seton removal alone [control group] with AFP insertion [AFP group] in 106 Crohn's disease patients with non- or mildly active disease having at least one ano-perineal fistula tract drained for more than 1 month. Patients with abscess [collection ≥ 3mm on magnetic resonance imaging or recto-vaginal fistulas were excluded. Randomisation was stratified in simple or complex fistulas according to AGA classification. Primary end point was fistula closure at Week 12.

Results: In all, 54 patients were randomised to AFP group [control group 52]. Median fistula duration was 23 [10-53] months. Median Crohn's Disease Activity Index at baseline was 81 [45-135]. Fistula closure at Week 12 was achieved in 31.5% patients in the AFP group and in 23.1 % in the control group (relative risk [RR] stratified on AGA classification: 1.31; 95% confidence interval: 0.59-4.02; p = 0.19). No interaction in treatment effect with complexity stratum was found; 33.3% of patients with complex fistula and 30.8% of patients with simple fistula closed the tracts after AFP, as compared with 15.4% and 25.6% in controls, respectively [RR of success = 2.17 in complex fistula vs RR = 1.20 in simple fistula; p = 0.45]. Concerning safety, at Week 12, 17 patients developed at least one adverse event in the AFP group vs 8 in the controls [p = 0.07].

Conclusion: AFP is not more effective than seton removal alone to achieve FAP-CD closure.