Flexible Spectral Imaging Color Enhancement and Probe-based Confocal Laser Endomicroscopy in Minimal Change Esophageal Reflux Disease.

BACKGROUND/AIMS Although flexible spectral imaging color enhancement (FICE) can facilitate the diagnosis of minimal change esophageal reflux disease (MERD), the complicated diagnostic criteria cause suboptimal inter-observer agreement. Confocal laser endomicroscopy (CLE) yields good diagnostic results but its inter-observer agreement has never been explored. This study compares the diagnostic value of magnifying FICE and probe-based CLE (pCLE) for MERD and evaluates the inter-observer agreement of both techniques. METHODS Thirty-six patients with suspected MERD and 18 asymptomatic controls were recruited. Magnifying FICE was used for evaluation of distal esophagus. pCLE counted the number of intrapapillary capillary loops (IPCLs) using more than five IPCLs in 500×500 micron area as a criterion for MERD diagnosis. The validity scores and interobserever agreement of both FICE and pCLE were assessed. RESULTS For FICE vs. pCLE, the accuracy was 79% vs. 87%, sensitivity 94% vs. 97%, specificity 50% vs. 66%, positive predictive value 79% vs. 85%, and negative predictive value 82% vs. 92%. Interobserver agreement of FICE was fair to substantial, whereas pCLE had substantial to almost perfect agreement. CONCLUSIONS Both FICE and pCLE have good operating characteristics and can facilitate the MERD diagnosis. However, among different observers, pCLE is more consistent on MERD diagnosis.