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

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].

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.

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].

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