Clinical Factors Associated with Missing Colorectal Polyp on Colon Capsule Endoscopy

Background: There are a number of reports that demonstrate the high diagnostic accuracy of colon capsule endoscopy (CCE) for polyp detection. However, some colorectal polyps are missed on CCE, and the clinical factors influencing those missed polyps are still unknown. Objective: The aim of this study was to elucidate the clinical factors related to missing colorectal polyp on CCE by using per-polyp analysis. Methods: We performed a retrospective multi-center study of 53 consecutive patients who underwent both CCE and colonoscopy (CS) within 3 months from January 2014 to-December 2017. Of those patients, we analyzed 151 polyps detected on CCE, and 149 polyps detected on CS diagnosed as neoplasm according to histopathological result. Results: The capsule excretion rate was 81%. One hundred three polyps were detected on both CS and CCE, 46 polyps (31%) were missed on CCE, and 48 polyps were considered false positive on CCE when CS result was considered as the gold standard. Per-polyp sensitivity and positive predictive value on CCE were 69.1 and 68%. On multiple logistic analysis, only the segmental transit time on CCE was identified as the independent factor influencing missed polyp on CCE. Conclusions: The clinical factor related to missing colorectal polyp on CCE was the segmental transit time.