Prospective multicenter performance evaluation of the second-generation colon capsule compared with colonoscopy

Background and study aims: A second-generation capsule endoscopy system, using the PillCam Colon 2, was developed to increase sensitivity for colorectal polyp detection compared with the first-generation system. The performance of this new system is reported. Patients and methods: In a five-center feasibility study, second-generation capsule endoscopy was prospectively compared with conventional colonoscopy as gold standard for the detection of colorectal polyps and other colonic disease, in a cohort of patients scheduled for colonoscopy and having known or suspected colonic disease. Colonoscopy was independently performed within 10 hours after capsule ingestion. Capsule-positive but colonoscopy-negative cases were counted as false-positive. Results: 104 patients (mean age 49.8 years) were enrolled; data from 98 were analyzed. Patient rate for polyps of any size was 44%, 53% of these patients having adenomas. No adverse events related to either procedure were reported. The capsule sensitivity for the detection of patients with polyps 6mm was 89% (95% confidence interval [CI] 7097) and for those with polyps 10mm it was 88% (95%CI 5698), with specificities of 76% (95%CI 7278) and 89% (95%CI 8690), respectively. Both polyps missed by colonoscopy and mismatch in polyp size by study definition lowered specificity. Overall colon cleanliness for capsule endoscopy was adequate in 78% of patients (95%CI 6886). Conclusions: The new second-generation colon capsule endoscopy is a safe and effective method for visualizing the colon and detecting colonic lesions. Sensitivity and specificity for detecting colorectal polyps appear to be very good, suggesting a potential for improved accuracy compared with the first-generation system. Further prospective and comparative studies are needed.