Polyps seen but not removed during index colonoscopy: an underestimated inefficiency in endoscopy practice

In the United Kingdom endoscopists are certified for independent practice once competent in the removal of polyps up to 20 mm in size. Where polyps are detected but not removed during the index colonoscopy, a repeat procedure is required. The aim of this study was to identify the proportion of polyps <20 mm that were not removed at the time of diagnosis.

Polyps identified at colonoscopy during a 12-month period in a single institution were included in this study. All polyps were categorized according to the reported size and complexity per the size, morphology, site, access (SMSA) classification. In cases where polyps ≤20 mm were not removed, patient records and endoscopy reports were interrogated to ascertain the reasons for this.

Across 1444 patients, 2442 polyps <20 mm in size were diagnosed. Removal at the time of the index procedure occurred in 1158 patients (80.2%). Nonremoval for a predefined acceptable reason, such as concomitant anticoagulation therapy, accounted for 174 cases (12.0%). Nonremoval without contraindication was noted in 112 cases (7.8%). The mean polypectomy complexity as determined by the SMSA score of these polyps was lower than level 2, denoting low complexity. The requirement for unnecessary repeat procedures equated to 9.3 days of endoscopy capacity per year.

This study demonstrates that a small but significant proportion of small colorectal polyps are not removed at the time of diagnosis. This practice has implications for both patients and service provision.