Risk factors for polyp retrieval failure in colonoscopy

Introduction: Colonoscopy is able to diagnose, resect and retrieve colonic polyps. Although retrieval of resected polyps is still globally advised, it is not always successful. We aimed to define the risk factors for polyp retrieval failure in colonoscopy. Methods: A single-center, retrospective study assessed 3507 consecutive and non-urgent colonoscopies, performed between September 2011 and December 2012. Colonoscopies were included in our analysis if the diagnosis of at least one polyp was established, and one or more snare polypectomies were performed. Demographic and technical data were collected according to the patient's endoscopy report. Results: A total of 1109 polyps were analyzed, corresponding to 496 colonoscopies from 483 different patients. We found that 53 (4.8%) of the resected polyps were not retrieved. In a univariate analysis, the factors associated with polyp retrieval failure were: age, polyp size, resection technique, bowel preparation, location and the presence of a previous colorectal surgery (p<0.05). In the multivariate analysis, a previous colorectal surgery, resection by cold snare, location in the right colon, inadequate bowel preparation and a polyp size up to 5mm were independently associated with higher polyp retrieval failure (p<0.05). Discussion: Different and well-defined factors were associated with polyp retrieval failure. Because bowel preparation was the only modifiable factor identified, a special focus should be given to this topic.