ENDOSCOPIC FACTORS IN THE DIAGNOSIS OF COLORECTAL DYSPLASIA IN CHRONIC INFLAMMATORY BOWEL DISEASE

Abstract

Purpose: We sought to determine if any procedure-related factors during surveillance colonoscopy were associated with the diagnosis of colorectal neoplasia. Methods: We reviewed the Mayo Clinic endoscopic database and medical records of patients with IBD who underwent surveillance colonoscopy between January 2002 and November 2003. Associations were sought between procedure-related variables and the diagnosis of dysplasia. Results: We evaluated 757 surveillance colonoscopies carried out in 635 patients. Five hundred thirty five patients with ulcerative colitis, 93 patients with Crohn's disease and 7 patients with indeterminate colitis were evaluated retrospectively. The median age of the patients enrolled in the study was 51 years (range 19–87). Among 635 IBD patients, 24 (3.8%) had flat dysplasia and 12 (1.9%) had IBD-related polypoid dysplasia. In 28 patients (4.4%), sporadic tubular adenoma was identified. Eighty-three patients had inflammatory orhyperplastic polyps that were biopsied or removed during the procedure. The median total procedure duration for surveillance colonoscopy in this study was 23 minutes. The presence of polyps appeared to lengthen the procedure, with a median procedure duration of 30 minutes (range 2–74) compared to 22 minutes (range 3–81) in colonoscopies without polyps, p <0.0001. Colonoscopies in which flat dysplasia was identified took a median duration of 24.5 minutes (range 7–81), compared to 22 minutes (range 3–70) for those in which dysplasia was not found. Using logistic regression analysis, we found that every additional minute in total colonoscopy time increased the flat dysplasia diagnosis rate by 3.5%, p = 0.0157. There was a significant correlation between median surveillance colonoscopy duration per endoscopist and flat dysplasia diagnosis rate, p = 0.0066. The median number of biopsies obtained per procedure was 25, range 2–54. There was no significant difference in the median number of biopsies taken during the procedures with (28, range 6–36) and without (25, range 2–54) flat dysplasia. Conclusions: There is variance in surveillance colonoscopy practice even in the same institution among endoscopists. Spending more time during surveillance colonoscopy of IBD might increase dysplasia yield.