Colonoscopy quality assessment and accuracy: analysis of the influencing factors and surgical sequelae on 216 colonoscopies

OBJECTIVE: Colonoscopy is recognized as the primary screening test for colorectal cancer. However, its inaccuracy in identifying the exact tumor localization is still high. As a consequence, repeated colonoscopies and changes in the surgical management have been reported. This study aims to evaluate the quality of 216 colonoscopies, to define colonoscopy accuracy and to investigate the surgical sequelae of an incorrect localization.PATIENTS AND METHODS: A retrospective analysis of 216 colonoscopies has been conducted. Colonoscopy quality was assessed on: quality of bowel preparation, completeness of the examination, video and/or photographic documentation, and reported the distance of the lesion from the anal verge. Colonoscopy accuracy was evaluated in terms of correspondence between the endoscopic and intra-operative tumor localization.RESULTS: Bowel preparation adequateness was reported in 121 out of 216 (56%) colonoscopies, with an adequate grade in 68.6% of cases. A complete colonoscopy was accomplished in 86.9% of cases with photo documentation in only 59 colonoscopies (27.3%). The lesion distance from the anal verge was documented only in 93 out of 216 colonoscopies. Of the 157 lesions described at the colonoscopy, 117 matched with the intra- operative localization (accuracy 74.5%). Fifteen of the 40 incorrectly localized lesions (37.5%) required changes in the surgical management. At multivariate analysis, the colonoscopy completeness was the only influencing factor on the concordance between endoscopic and intra- operative localization.CONCLUSIONS: Colonoscopy demonstrated adequate accuracy in localizing lesions. However, the incorrect tumor localization leads to a high rate of changes in surgical management. Increase in colonoscopy quality is needed to reduce the risk of incorrect localizations.