Feasibility of a second-generation colon capsule in visualization of the upper gastrointestinal tract

BACKGROUND: Capsule endoscopy for visualization of the entire gastrointestinal tract is a challenge. A second-generation colon capsule endoscopy system (CCE-2) performed well in the colon and small intestine, but its utility in the upper gastrointestinal duct is not clear. We evaluated the use of the CCE-2 in the visualization of the upper gastrointestinal tract. METHODS: We performed a retrospective study and further evaluated CCE-2 images using the typical landmarks of esophagus and stomach. The two imagers located at each end of the CCE-2 system were defined as imager1 (green) and imager2 (yellow). Two endoscopists read the images, and they were blinded to the other reader’s results. All of the images from the two imagers were separately reviewed. RESULTS: Images from 127 subjects were analyzed. This study demonstrated the comprehensive visualization of 71.7% of esophageal landmarks and 89.8% of gastric landmarks using the CCE-2. The two CCE-2 imagers were not identical, and the lighter imager (imager2, yellow) was superior to the heavier imager (imager1, green) (78% vs. 33.1%) in the stomach. Compared with the use of one imager, the use of two imagers was superior (two-imager vs. imager1, 89.8% vs. 33.1%; two-imager vs. imager2, 89.8% vs. 78%) in the stomach. Two-imager combination analysis detected a total of 160 positive findings. In contrast, single-imager analysis with imager1 and imager2 detected 133 and 137 findings, respectively. Two-imager combination analysis provided 20.3% and 16.8% more findings than imager1 and imager2, respectively. The two imagers complemented each other to detect more lesions. CONCLUSIONS: The CCE-2 system is feasible for use in the upper gastrointestinal tract and may be considered an optional tool for upper gastrointestinal imaging. This system may represent a good choice for complete gastrointestinal duct screening. Compared with the use of one imager, the two-imager combination provided improved upper gastrointestinal tract mucosal visualization.