Virtual Versus Dye-based Chromoendoscopy in Inflammatory Bowel Disease Surveillance Colonoscopy

This is a multicenter, prospective, randomized, non-inferiority clinical trial designed to compare the diagnostic performance of two high-definition endoscopic imaging techniques used during surveillance colonoscopy in patients with longstanding inflammatory bowel disease (IBD) who are at increased risk for colorectal cancer. Participants will be randomly assigned to undergo colonoscopy using either a virtual (dye-free) chromoendoscopy method or a conventional dye-based chromoendoscopy technique. The primary objective is to evaluate whether virtual chromoendoscopy is non-inferior to dye- based chromoendoscopy in detecting dysplasia, a precancerous condition in the colon. Secondary outcomes include the number and type of lesions detected, predictive accuracy of targeted biopsies, examination times, patient-reported experience, complication rates, and biopsy frequency. Eligible participants are adults with a history of extensive colonic IBD of at least eight years, or additional high-risk factors such as primary sclerosing cholangitis or family history of colorectal cancer. Patients with previous colorectal cancer, prior colectomy, known untreated dysplasia, or contraindications to dye application will be excluded. All procedures will be performed using high-definition equipment and standardized bowel preparation protocols. The study includes long-term follow-up through national health registries to evaluate cancer outcomes and subsequent procedures at one and three years post-colonoscopy. The trial will be conducted across several academic and regional centers in Sweden, with an anticipated enrollment of approximately 480 patients to account for potential attrition. This study seeks to inform future guidelines by determining whether a less resource-intensive and potentially more patient-friendly method can provide equivalent surveillance efficacy in this high-risk population.

Inclusion criteria

• Age ≥ 18 years and one of the criteria beneath:
• Extensive ulcerative colitis or indeterminate colitis (IBD-U), or Crohn's colitis involving at least one-third of the colon, with a disease history of at least 8 years
• IBD or IBD-U with primary sclerosing cholangitis (PSC)
• IBD or IBD-U with a family history of colorectal cancer in a first-degree relative

Exclusion criteria

• History of colorectal cancer or prior colectomy
• Contraindications to dye use
• Colonoscopies for therapeutic purposes
• Pregnancy
• Inability to consent