Chromoendoscopy for Dysplasia Detection in Chronic Inflammatory Bowel Disease

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.

Patients with longstanding ulcerative colitis or crohn's disease in the large bowel have an increased risk of developing cancer. The purpose of this study is to determine if visualizing of the mucosa in details using a dye spray (indigo-carmine) will result in detection of more abnormalities than conventional colonoscopy without dye spray.

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 biopsies.

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 unknown.

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.

Inclusion Criteria:

Patients with ulcerative colitis or Crohn's colitis satisfying criteria for surveillance colonoscopy:

• Ulcerative colitis, extensive > 8 years OR Crohn's colitis involving ≥ 1/3 of colon/rectum
• history of PSC or
• history of previous dysplasia on colon biopsies or
• family history of colon cancer in first degree relative

Exclusion Criteria:

• Patients who decline to participate
• Unable to give informed consent
• Increased risk of bleeding (i.e. Warfarin, bleeding disorders, Clopidogrel)