COLONOSCOPIC MISS RATES OF ADENOMAS DETERMINED BY BACK-TO-BACK COLONOSCOPIES

Background & Aims: The miss rate of colonoscopy for neoplasms is poorl y understood, The aim of this study was to determine the miss rate of colonoscopy by same day back-to-back colonoscopy. Methods: Two consecu tive same day colonoscopies were performed in 183 patients, The patien ts were randomized to undergo the second colonoscopy by the same or a different endoscopist and in the same or different position, Results: The overall miss rate far adenomas was 24%, 27% for adenomas less than or equal to 5 mm, 13% for adenomas 6-9 mm, and 6% for adenomas greate r than or equal to 1 cm. Patients with two or more adenomas at the fir st examination were more likely than patients with no or one adenoma d etected at the first examination to have one or more adenomas at the s econd examination (odds ratio, 3.3; 95% confidence interval, 1.69-6.46 ), Right colon adenomas were missed more often (27%) than left colon a denomas (21%), but the difference was not significant, There was evide nce of variation in sensitivity between endoscopists, but significant miss rates for small adenomas were found among essentially all endosco pists. Conclusions: Using current colonoscopic technology, there are s ignificant miss rates for adenomas <1 cm even with meticulous colonosc opy, Miss rates are low for adenomas greater than or equal to 1 cm. Th e results suggest the need for improvements in colonoscopic technology .