대장내시경에 의한 용종의 간과율

Abstract

<Background or Introduction> Colonoscopy is useful for the detection and removal of colonic polyps but the problems in quality control of colonoscopy is rising as the number of colonoscopic examinations increases as a result of increased health promotion programs. Although many studies determined by tandem colonoscopy reports that the polyp miss rates by colonoscopy are approximately 25%, the miss rates are not clear since there is no gold standard to diagnose colonic polyps comparable to colonoscopy. Our study compared the number of polyps found by colonoscopy with the number of polyps in surgically resected colon to investigate how frequently colonoscopy might miss polyps and which factors could affect the polyp miss rate by colonoscopy. <Materials and Methods > We retrospectively analysed 38 patients who underwent colon resection for colorectal cancer and had synchronous lesions in the resected portion. The miss rate was determined by comparing the number of polyps detected at colonoscopy with those present in the resected colonic segment. A statistical analysis was made about the influences of the location, the pathologic type, or the size of missed polyps on the colonoscopic miss rates. <Results> The number of polyps found in resected colon specimen were 93, 68 of which were detected at colonoscopy, so the overall miss rate by colonoscopy was 26.9%. Of 25 polyps missed at colonoscopy, 1 were ≥ 10 mm in size and 24 were < 10 mm. 9 of 69 adenomatous polyps were missed by colonoscopy, while colonoscopy missed 15 of 18 hyperplastic polyps. In the descending, transverse, ascending and sigmoid colon the miss rates were 0%, 29%, 17%, 22% respectively. Conclusively, <10 mm polyps, hyperplastic polyps, those in rectum and cecum were more frequently missed in our study. <Conclusions> Colonoscopy is an effective method to diagnose and treat polyps but we should not miss the significant miss rates of polyps by colonoscopy. Endoscopists should pay more attention to find synchronous lesions in patients with known colorectal cancers, and not only technical advances but also quality control of colonoscopy is highly warranted not to miss these synchronous lesions.