Usefulness of virtual scale endoscope for early gastrointestinal lesions

Objectives: For early gastrointestinal lesions, size is an important factor in the selection of treatment. Virtual scale endoscope (VSE) is a newly developed endoscope that can measure size more accurately than visual measurement. This study aimed to investigate whether VSE measurement is accurate for early gastrointestinal lesions of various sizes and morphologies. Methods: This study prospectively enrolled patients with early gastrointestinal lesions <= 20 mm in size visually. Lesion sizes were measured in the gastrointestinal tract visually, on endoscopic resection specimens with VSE, and finally on endoscopic resection specimens using a ruler. The primary endpoint was the normalized difference (ND) of VSE measurement. The secondary endpoints were the ND of visual measurement and the variation between NDs of VSE and visual measurements. ND was calculated as (100 x [measured size - true size] / true size) (%). True size was defined as size measured using a ruler. Results: This study included 60 lesions from April 2022 to December 2022, with 20 each in the esophagus, stomach, and colon. The lesion size was 14.0 +/- 6.3 mm (mean +/- standard deviation). Morphologies were protruded, slightly elevated, and flat or slightly depressed type in 8, 24, and 28 lesions, respectively. The primary endpoint was 0.3 +/- 8.8%. In the secondary endpoints, the ND of visual measurement was -1.7 +/- 29.3%, and the variability was significantly smaller in the ND of VSE measurement than in that of visual measurement (p < 0.001, F-test). Conclusions: VSE measurement is accurate for early gastrointestinal lesions of various sizes and morphologies.