New Classification of Gastric Pit Patterns and Vessel Architecture Using Probe-based Confocal Laser Endomicroscopy

Goals: To propose a new probe-based confocal laser endomicroscopy (pCLE) classification of gastric pit patterns and vessel architecture, and to assess the accuracy and interobserver agreement. Background: pCLE is a newly developed endoscopic device that allows the application of laser microscopy with any conventional endoscope and mosaic imaging. Study: A total of 291 pCLE videos from 32 patients were recruited in phase I to establish the new pCLE image classification in the stomach. Eligible patients were then prospectively investigated by pCLE using the newly established classification system. All patients were examined first with high-definition endoscopy followed by pCLE at 7 standardized locations and endoscopic-suspected lesions. Targeted biopsies were performed with precise matching of pCLE recordings. Results: The sensitivity and specificity of type 2b pit pattern for predicting atrophic gastritis were 88.51% and 99.19%, respectively. The sensitivity and specificity of type 2c pit pattern for predicting intestinal metaplasia were 92.34% and 99.34%, respectively. The overall sensitivity and specificity of type 3 pit pattern or vessel architecture for predicting neoplasia were 89.89% and 99.44%, respectively. The interobserver agreement was "substantial" (kappa = 0.70) for the differentiation of neoplasia versus non-neoplasia. Conclusions: The new pCLE classification system in the stomach correlates well with specific pathologic conditions and is reproducible by multiple investigators. Multicenter researches are warranted to further validate its value in clinical practice.