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 ≥ 6 mm was 89 % (95 % confidence interval [CI] 70 – 97) and for those with polyps ≥ 10 mm it was 88 % (95 %CI 56 – 98), with specificities of 76 % (95 %CI 72 – 78) and 89 % (95 %CI 86 – 90), 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 68 – 86).

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.

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