TIPS AND POINTS FOR ENDOSCOPIC SUBMUCOSAL DISSECTION OF BARRETT’S ESOPHAGEAL ADENOCARCINOMA

Abstract

In Barrettʼs esophageal adenocarcinoma (EAC), particularly those arising from long-segment Barrettʼs esophagus (LSBE), there are many cases of Ⅱb spreading and it is difficult to diagnose lateral extension. Therefore, in cases of EAC derived from LSBE with an unclear margin, it is necessary to confirm the lateral extension by taking biopsy samples from areas outside of the lesion. In EAC that abuts the squamocolumnar junction (SCJ), EAC often extends under the squamous epithelium. Endoscopic findings of sub-epithelial invasion include changes in color of the mucosa, and the appearance of abnormal blood vessels and small holes. However, some cases do not develop these features. The mean distance of sub-epithelial invasion of short-segment Barrettʼs esophagus (SSBE) and LSBE is 4 (1-12, range) and 5 (1-20) mm, respectively. Therefore, an enough safety margin should be kept for LSBE.

Endoscopic submucosal dissection (ESD) of EAC is more difficult than that of squamous cell carcinoma (SCC) because of submucosal fibrosis caused by reflux esophagitis or ulcer scar in EAC.

In Western countries, radiofrequency ablation (RFA) for residual Barrettʼs mucosa is recommended after endoscopic treatment of a visible lesion because the rate of metachronous cancer of EAC is high (10.3～21.5%). However, RFA ablates only the surface layer and Barrettʼs epithelium sometimes remains in the deep mucosa after RFA. It is necessary to be aware that RFA cannot always eradicate Barrettʼs epithelium. Japanese guidelines recommend careful follow-up observation. However, in order to prevent metachronous EAC, we have been performing circumferential ESD or stepwise radical ESD for the treatment of EAC.