Multicenter prospective registration study of efficacy and safety of capsule endoscopy in Crohn’s disease in Japan (SPREAD-J study)

BACKGROUND: Evidence of small-bowel capsule endoscopy (SBCE) for evaluating lesions in Crohn’s disease (CD) is lacking. We aimed to clarify the effectiveness and safety of SBCE in a large sample of patients with CD. METHODS: This multicenter prospective registration study recorded the clinical information and SBCE results of patients with definitive CD (d-CD) or suspected CD (s-CD). The primary outcomes were the rates of successful assessment of disease activity using SBCE, definitive diagnosis of CD, and adverse events. Secondary outcomes were the assessment of SBCE findings in patients with d-CD and s-CD and factors affecting SBCE incompletion and retention; and tertiary outcomes included the association between clinical disease activity or blood examination, endoscopic disease activity, ileal CD, and the questionnaire assessment of patient acceptance of SBCE. RESULTS: Of 544 patients analyzed, 541 underwent SBCE with 7 (1.3%) retention cases. Of 468 patients with d-CD, 97.6% could be evaluated for endoscopic activity. Of 76 patients with s-CD, 15.8% were diagnosed with ‘confirmed CD’. CD lesions were more frequently observed in the ileum and were only seen in the jejunum in 3.4% of the patients. Male sex and stenosis were risk factors for incomplete SBCE, and high C-reactive protein levels and stenosis were risk factors for capsule retention. In L1 (Montreal classification) patients, clinical remission was associated with endoscopic remission but showed low specificity and accuracy. The answers to the acceptability questionnaire showed the minimal invasiveness and tolerability of SBCE. CONCLUSION: SBCE is practical and safe in patients with CD. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s00535-023-02017-3.