Video capsule endoscopy can identify occult luminal Crohn's disease in patients with isolated perianal fistulas.

Abstract

Accurate tools to distinguish Crohn's disease (CD) from cryptoglandular disease in patients with perianal fistulas without detectable luminal inflammation on ileocolonoscopy and abdominal enterography (isolated perianal fistulas [IPF]) are lacking. We assessed the ability of video capsule endoscopy (VCE) to detect luminal inflammation in patients with IPF. We studied consecutive adults (>17 years) with IPF who were evaluated by VCE after a negative ileocolonoscopy and abdominal enterography between 2013 and 2022. We defined luminal CD by VCE as diffuse erythema, three or more aphthous ulcers, or a Lewis score greater than 135. We compared rates of intestinal inflammation in this cohort to age- and sex-matched controls without perianal fistulas who underwent VCE for other indications. We excluded persons with pre-existing IBD and exposure to non-steroidal anti-inflammatories drugs or immunosuppressive treatments. A total of 45 patients with IPF underwent VCE without complications. Twelve patients (26%) met our definition of luminal CD. Luminal CD was more common in patients with IPF than controls (26% vs. 3%; p < 0.01). Among patients with IPF, male sex (OR, 9.2; 95% CI (1.1-79.4), smoking (OR, 4.5; 95% CI, 0.9-21.2), abscess (OR, 6.3; 95% CI (1.5-26.8), rectal enhancement on MRI (OR, 9.0; 95% CI (0.8-99.3) and positive anti-microbial serology (OR, 7.1; 95% CI, 0.7-70.0) were more common in those with a positive VCE study. VCE detected small intestinal inflammation suggestive of luminal CD in approximately one quarter of patients with IPF. Larger studies are required to validate these findings.