Distribution, size and shape of colorectal adenomas as determined by a colonoscopist with a high lesion detection rate: Influence of age, sex and colonoscopy indication

Abstract

Background: Increasing attention is focused on polyp-related features that may contribute to the operator-dependent nature of colonoscopy. Few data on polyps are available from high-yield colonoscopies, which may serve as a benchmark for quality control. Objectives: Describe regional distribution, histology, size and shape of polyps, and the influence of patient age and gender, in colonoscopies performed by a colonoscopist with high lesion detection rate. Methods: Analysis of 698 consecutive patients with diagnostic, screening or surveillance colonoscopies. Results: In 704 colonoscopies, 1908 polyps were removed (360 were protruded and 1548 flat; 1313 were hyperplastic, 562 adenomas, 5 serrated adenomas and 8 mixed). There were 232 adenomas in female patients and 343 in male patients; 39% of the adenomas were protruded and 61% were flat. The peak adenoma detection rate (ADR) was 51% in patients beyond age 79 years. Men older than 49 years had a higher ADR than women. In men and women, respectively: 40% and 32% of adenomas were in the right colon, 31% and 22% were in the transverse colon, and 30% and 47% were in the left colon. Beyond age 59 years, the majority of adenomas were in the proximal colon. Conclusions: An excess of adenomas in the proximal colon started at age 60 and this was more pronounced in men than in women. In all colonic regions, the majority of adenomas had a shape that was flat and smaller than 6 mm.