Screening and surveillance colonoscopy in chronic Crohn's colitis

Unlike ulcerative colitis, there are few reports on the efficacy of surveillance colonoscopy in patients with chronic Crohn's colitis and therefore little agreement as to whether routine surveillance is indicated. We report on 259 patients with chronic Crohn's colitis who underwent screening and subsequent surveillance colonoscopy and biopsy since 1980.

Biopsies were performed at 10-cm intervals and from strictures and polypoid masses. Pathology was classified as normal, dysplasia (indefinite, low-grade, high-grade), or carcinoma.

A total of 663 examinations were performed on 259 patients. The median interval between examinations was 24 months; examinations were performed more frequently (1-6 months) in patients with dysplasia on biopsy. A thinner-caliber colonoscope was required to complete 12% of screening examinations and 23% of surveillance examinations. The pediatric colonoscope helped increase our yield of neoplasia by 19%. The screening and surveillance program detected dysplasia or cancer in 16% (10 indefinite, 23 low-grade, and 4 high-grade dysplasias and 5 cancers). A finding of definite dysplasia or cancer was associated with age >45 years and increased symptoms. By life table analysis, the probability of detecting dysplasia or cancer after a negative screening colonoscopy was 22% by the fourth surveillance examination.

Colonoscopic surveillance should be strongly considered in chronic extensive Crohn's colitis.