Archive | 2019
Esophageal Mucosa in Health and Disease
Abstract
Abstract The area distal to the end of the tubular esophagus is confusing and controversial. Existing viewpoints that cardiac epithelium normally lines the proximal stomach and that the gastroesophageal junction (GEJ) is accurately defined at endoscopy by the proximal limit of rugal folds are not evidence based. Correction of these errors results in the recognition that the normal state is an esophagus that is entirely tubular and lined by squamous epithelium while the stomach is lined by gastric oxyntic epithelium. Cardiac epithelium always results from metaplasia of esophageal squamous epithelium when it is exposed to gastric juice. Cardiac metaplasia of esophageal squamous epithelium results in loss of lower esophageal sphincter (LES) pressure and dilatation of the esophagus. Measurement of cardiac epithelium distal to the endoscopic GEJ is an exact histologic measure of damage to the abdominal segment of the LES. Gastroesophageal reflux disease, when viewed from the perspective of LES damage, is an inexorably progressive disease whose progression varies with the rate of progression of LES damage. This permits recognition of the root cause of gastroesophageal reflux disease (GERD) at its earliest preclinical stage, providing a new method of early diagnosis and intervention designed to prevent complications of GERD. This has the potential to prevent esophageal adenocarcinoma.