Risk factors associated with missed colorectal lesions in colonoscopy and impact of colonoscopy with anesthesia on miss rate.

OBJECTIVES: To systematically determine the miss rate and risk factors for polyps, adenomas and advanced adenomas in the same population, and to further analyze the impact of colonoscopy with anesthesia on miss rate. METHODS: We retrospectively analyzed the information of the patients undergoing the second colonoscopy within 1 year after their first. The patient and lesion miss rate were calculated. The patient and lesion features of missed lesion were compared with non-missed lesion. Finally, the patients were divided into anesthesia group and without anesthesia group, and the impact of colonoscopy with anesthesia on missed lesions was further analyzed. RESULTS: The patient miss rate of polyps, adenomas and advanced adenomas was 32.8, 25.6 and 10.4%, and the lesions miss rate was 19.6, 15.8 and 7.2%. In multivariable logistic regression analysis, lesion-related factors (large number of lesions, small lesion size, flat shape and location at the right colon) and patient-related factors (male, elder, abdominal symptoms, surgical history, diverticulum, colonoscopy without anesthesia and suboptimal bowel preparation) were found to be independently associated with missed polyps and adenomas (p < .05). Large number of lesions, flat shape and suboptimal bowel preparation were associated with missed advanced adenoma (p < .05). Colonoscopy with anesthesia can reduce the polyp miss rate (PMR) and male and elderly patients are more likely to be missed during colonoscopy without anesthesia. CONCLUSIONS: Many factors of patients and lesions can affect the lesions miss rate. Colonoscopy with anesthesia can reduce the PMR and male and elderly patients are more likely to be missed during colonoscopy without anesthesia.