Narrow band imaging does not reliably predict residual intestinal metaplasia after radiofrequency ablation at the neo-squamo columnar junction

Abstract

After radiofrequency ablation (RFA) of Barrett's esophagus, it may be difficult to determine whether complete eradication of intestinal metaplasia at the neosquamocolumnar junction (neo-SCJ) in the cardia has been achieved. It is claimed that narrow band imaging (NBI) may predict the presence of intestinal metaplasia, which would enable immediate treatment. The aim of the current study was to evaluate whether inspection of the neo-SCJ with NBI after RFA results in reliable detection of intestinal metaplasia. Patients with a normal-appearing neo-SCJ who were scheduled for RFA were included in the study. Two expert endoscopists obtained images from the neo-SCJ in overview (high resolution white light and NBI mode) and from four areas using NBI zoom, followed by corresponding biopsies. Four other blinded expert endoscopists evaluated the images for the presence of intestinal metaplasia and type of mucosal pattern (round, small tubular, large tubular, villous). Endpoints were sensitivity and specificity for identifying patients and areas with intestinal metaplasia. From 21 patients overview images from 21 neo-SCJs and NBI zoom images from 83 neo-SCJ areas were obtained. Intestinal metaplasia was present in five overview images (24 %) and nine zoom images (11 %). Using the overview images, sensitivity and specificity for identifying patients with intestinal metaplasia were 65 % (95 % confidence interval [CI] 38 - 86) and 46 % (95 %CI 33 - 60), respectively. For individual zoom images, sensitivity was 71 % (95 %CI 54 - 85) and specificity was 37 % (95 %CI 32 - 43). After RFA, endoscopic inspection of the neo-SCJ with NBI in overview or zoom does not reliably predict presence or absence of intestinal metaplasia.