Perianal and Luminal Relapse Following Perianal Surgical Intervention in Crohn's Disease.

Background And Aims: Fistula relapse occurs in 20-30% of patients with perianal Crohn's disease (PCD) despite optimal medico-surgical management. We aimed in this study to assess the rate of perianal and luminal relapse after surgically induced remission and to determine factors associated with fistula relapse.

Methods: Consecutive perianal CD patients who achieved clinical remission after surgery for fistulising PCD from January 2013 to January 2019 were included. The cumulative probabilities of relapse-free survival were estimated using the Kaplan-Meier method.

Results: A total of 130 patients were included. Sixty-six of 130 patients received infliximab (IFX) therapy after perianal surgery. After a median follow-up of 62 months (interquartile range [IQR]: 28-117 months), perianal relapse occurred in 30 of 64 (46.9%) nonbiological medication-treated cases and in 14 of 66 (21.1%) cases in the IFX therapy group. The cumulative probabilities of perianal relapse-free survival in patients with nonbiological treatment were 77.1% at 1 year, 54.6% at 3 years, and 30% at 5 years. The rates of survival without perianal fistula relapse in the IFX-treated group were 91.6%, 69.2%, and 59.3% at 1, 3 and 5 years, respectively. In patients treated with IFX after perianal surgery, discontinuation of IFX therapy (odds ratio [OR]=2.43, p=0.036), a penetrating CD phenotype (OR=4.324, =0.019), and a complex perianal fistula (OR=3.392, =0.026) were independently associated with perianal relapse in multivariate analysis.

Conclusion: Infliximab therapy reduced the risk of perianal relapse after surgical remission in PCD patients compared with nonbiological treatment. However, approximately 40% of patients using infliximab experienced perianal relapse at 5 years, and patients who discontinued use of IFX or experienced a penetrating phenotype or a complex perianal fistula were associated with increased relapse rate.