Yield of Random Biopsies During Colonoscopies in Inflammatory Bowel Disease Patients Undergoing Dysplasia Surveillance.

backgroundThe development of chromoendoscopy (CE) and high definition endoscopy (HDE) has improved detection of subtle colonic dysplasia in patients with inflammatory bowel diseases (IBDs). The role of random biopsies for dysplasia surveillance is unclear.

methodsWe reviewed patients with IBD who underwent a CE or HDE colonoscopy and had colonic dysplasia detected. Detection of dysplasia was classified as either visible or random and graded as low grade dysplasia (LGD), high grade dysplasia (HGD), or indefinite for dysplasia. Multivariable regression adjusted for relevant confounders examined the predictors of dysplasia detectable on random biopsies alone.

resultsThe study included 300 patients (203 ulcerative colitis, 97 Crohn's disease with colonic involvement) contributing 442 colonoscopies; the mean disease duration was 24.5 years; 7.2% had primary sclerosing cholangitis (PSC). Three hundred sixty-two colonoscopies (82%) had only visible dysplasia, 52 (12%) had only random dysplasia, and 28 (6%) had both visible and random dysplasia. Longer disease duration (odds ratio, 1.04; 95% CI, 1.01-1.07), active inflammation (odds ratio, 2.89; 95% CI, 1.26-6.67), and concomitant PSC (odds ratio, 3.66; 95% CI, 1.21-11.08) were associated with detecting dysplasia on random biopsies compared with visible lesions. Patients with random dysplasia (21%) or both random and visible dysplasia (21%) were more likely to undergo surgical resection compared with those with only visible dysplasia (5%; P < 0.001) and have subsequent development of colorectal cancer (15%, 7%, 1%, respectively; P < 0.0001).

conclusionNearly one fifth of dysplasia detected in patients with IBD was found on random biopsies. Patients with high risk characteristics may benefit from continuing the practice of random biopsies during surveillance examinations.