Radiofrequency Ablation and Dilated Columnar-Lined Esophagus

Abstract

To the Editor: It is with interest that we read the article by Pouw et al. (1) entitled Properties of the neosquamous epithelium after ablation of Barrett's esophagus containing neoplasia, which has been published in a recent issue of The American Journal of Gastroenterology. The fascinating finding of the study was that 2 years after radiofrequency ablation (RFA) for Barrett's esophagus containing dysplasia and early cancer, the esophagus was covered by a normal squamous epithelium. In addition to the normalization of histology (i.e., the absence of columnar-lined esophagus), genetic abnormalities had also been reversed (replacement with a normal stem cell pool). These outstanding data indicate that RFA is a promising tool for the effective endoscopic treatment of Barrett's esophagus and for the elimination of cancer risk. RFA eradicates columnar lining within the tubular esophagus. However, in patients with gastroesophageal reflux disease, the anatomical esophagogastric junction does not coincide with the level of the rise of endoscopically visible gastric-type folds (2). A segment of columnar-lined esophagus is interposed between the tubular esophagus and the proximal stomach (2). Because of the reflux-induced loss of the function of the lower esophageal sphincter and columnar lining, this part of the esophagus is dilated, resulting in a gastric-type appearance during endoscopy (i.e., columnar lining with gastric-type folds), which has therefore been named dilated end-stage esophagus (2). Recent studies indicated a similar oncological potential for columnar-lined esophagus with (Barrett's esophagus) and without intestinal metaplasia (i.e., cardiac and oxyntocardiac mucosa, respectively) (3). In addition, after RFA, patients are put on high-dose proton pump inhibitor therapy, which seems to favor the development of squamous epithelium within the ablated segments of the tubular esophagus (1,4). Due to its proximity to the stomach, the dilated end-stage esophagus is exposed to the highest concentrations of the oncogen (i.e., reflux) (2). Preexisting dysplasia and early cancer in the study by Pouw et al. (1) indicate that the esophageal mucosa (including the epithelium of the untreated dilated end-stage esophagus) was at an increased cancer risk. Supporting this notion, recent studies found that dysplasia was a significant risk factor for the development of esophageal adenocarcinoma (5,6). Because of saccular morphology, the dilated end-stage esophagus is not suitable for balloon catheter ablation (1,2). Therefore, an effective laparoscopic fundoplication around the dilated end-stage esophagus for the elimination of reflux should be considered after successful RFA. Otherwise, the development of adenocarcinomas within the untreated dilated columnar-lined esophagus may be observed. The authors are kindly asked to address the above considerations.