Wide Area Transepithelial Sampling (WATS3D) Improves Detection of Residual or Recurrent Intestinal Metaplasia Within the Tubular Esophagus and Squamocolumnar Junction

Abstract

Purpose: Barrett's esophagus (BE) is a pre-malignant condition defined as the presence of specialized intestinal metaplasia (IM) in the tubular esophagus. Radiofrequency ablation (RFA) and liquid nitrogen spray therapy (LN2SC) are used for endoscopic eradication of BE. Post-eradication surveillance endoscopy with biopsy is used to detect residual or recurrent intestinal metaplasia (IM). In patients with long segment BE (LSBE), data show forceps biopsies (FB) detected residual or recurrent IM at or near the neo-squamocolumnar junction (SCJ) (Shue at al, 2013). Our aim was to evaluate if WATS3D demonstrated similar patterns and/or improved detection within the tubular esophagus. Methods: Thirty-three LSBE patients treated with RFA or LN2SC underwent post-ablation endoscopy from May 2012 to May 2013. If there was no visual evidence of BE on white light endoscopy or narrow band imaging, WATS3D brush biopsy was performed using the standard 2-brush technique (EndoCDx®, CDx DiagnosticsTM, Suffern, NY). The SCJ was sampled with a separate brush set than the tubular esophagus. Brush samples were analyzed at a central laboratory using a neural network-based system that identifies abnormal cells and cell clusters for pathologist review. Four quadrant FB also were obtained every 1 cm for review by an expert GI pathologist. BE was defined for both techniques as the presence of goblet cell metaplasia. Analysis included comparison of both sample sets. Results: Thirty-three patients with visually eradicated LSBE underwent surveillance endoscopy (26 with RFA, seven with LN2SC). Residual or recurrent IM was detected on either FB or WATS3D in 12 cases (36.4%). Non-dysplastic IM was found only with FB in 5 cases: 4 at the SCJ and the other 2 cm proximal to the SCJ. In the six cases where IM was found only with WATS3D, a similar detection pattern was seen with five cases positive at the SCJ, and one at least 3 cm proximal to the SCJ. IM was detected on both FB and WATS3D in the final case, though FB detected non-dysplastic IM 2 cm proximal to the SCJ while WATS3D found high grade dysplasia at the SCJ. Overall, adjunct use of WATS3D with FB increased the detection rate by 50% (6/12). Conclusion: Both FB and WATS3D detect residual or recurrent IM following complete visual eradication of LSBE after RFA or LN2SC. Adjunct use of WATS3D not only increases detection at the SCJ, where most post-ablation IM is found, but also can identify IM higher in the tubular esophagus. Use of WATS3D may provide important information that changes the management of patients who were thought to have completed LSBE eradication. Disclosure - Dr. Smith - Consultant: CDx Laboratories, Inc.