IDDF2018-ABS-0222 Use of magnetic resonance imaging to evaluate the effectiveness of treatment for perianal fistulizing crohn’s disease

Abstract

Background Data on the radiologic evaluation of perianal fistulizing Crohn’s disease (PFCD) naive to anti-tumour necrosis factor therapy are scarce, especially in Asian populations. We assessed the effectiveness of infliximab (IFX) and azathioprine on PFCD and explored predictors of ‘deep remission’ based on clinical and radiologic assessments. Methods Patients with Crohn’s disease and active anal fistulas attending our centre for IFX therapy were prospectively enrolled. Each patient underwent clinical examination according to the Fistula Drainage Assessment Index, magnetic resonance imaging (MRI) to determine Van Assche score, Ng score, and main fistula length, endoscopy, assessment of Crohn’s disease activity index (CDAI) and perianal Crohn’s disease activity index (PCDAI), and laboratory tests up to 2 weeks prior to the start of and up to 2 weeks after the sixth IFX therapy (Week 32). Patients with PFCD treated with other medicines such as FK 506 or mesalazine and evaluated by two MRIs were retrospectively enrolled. Results Of 38 patients treated with IFX, 52.6% achieved clinical remission, and 42.1% achieved deep remission. The only predictor of deep remission was simple fistula (p=0.004, odds ratio=3.802, 95% confidence interval: 1.541–9.383). Van Assche score (from 14.5±4.26 to 7.36±7.53; figure 1), CDAI (from 170±92 to 71±69), and PCDAI (from 7.45±2.65 to 2.44±3.2) decreased significantly after six IFX treatments. Our findings suggest that Van Assche score has some limitations related to its inability to reflect new fistulas and abscesses in some circumstances. We used Ng score to compare the changes between the initial and follow-up MRIs in each patient, which is more objective and suitable for monitoring the therapeutic effect. Conclusions IFX is effective for the treatment of PFCD. MRI is the gold standard for evaluating PFCD, but Van Assche score has some limitations.