Randomized Controlled Trial (RCT) to Compare Dysplasia Detection Rate in Colonoscopy Without Chromoendoscopy Versus Colonoscopy With Chromoendoscopy in Detecting Dysplasia in Ulcerative Colitis and Crohn's Colitis Patients.
Background: Patients with ulcerative colitis and Crohn's colitis are at increased risk of
colon cancer. The usefulness of chromoendoscopy is debated. Previous studies are either
based on magnifying endoscopy or on non-randomized trials. Some guidelines recommend
chromoendoscopy with targeted biopsies and some normal colonoscopy with up to 40 random
Chromoendoscopy has the ability to identify subtle lesions that are otherwise missed by
standard endoscopy. Whether chromoendoscopy with targeted biopsies can replace standard
colonoscopy with random biopsies in the surveillance of patients with chronic colitis is
Aim: In a RCT in surveillance colonoscopies in patients with ulcerative colitis or Crohn's
colitis, we will determine if chromoendoscopy using a dilute solution of Indigo-carmine will
improve dysplasia detection rate compared with colonoscopy without chromoendoscopy.
Methods: After informed consent patients undergoing surveillance colonoscopy will be
randomized to be examined by the study or control method. The study method will employ a
0.2-0.5% Indigo-Carmine solution sprayed over the colonic and rectal mucosa. The control
method will be colonoscopy without Indigo-Carmine chromoendoscopy. In both the study arm and
the control arm all subjects will have 32 random biopsies taken (4 from each of 8 defined
segments of the colon) and biopsies from suspicious mucosa.
Allocation: Randomized, Endpoint Classification: Efficacy Study, Intervention Model: Parallel Assignment, Masking: Open Label, Primary Purpose: Diagnostic
Prevalence of dysplastic lesions
Number of patients with dysplastic lesions by colonoscopy with chromoendoscopy using Indigo-carmine versus colonoscopy without chromoendoscopy
Peter T Schmidt, MD, PhD
Karolinska University Hospital
Sweden: Regional Ethical Review Board