Definition of the Stomach and Esophagus

Abstract

It is difficult to believe that the medical community has reached the twenty-first century without a clear and accurate understanding of what the stomach and esophagus are. As with anything that does not have a standard definition, papers on diseases of the esophagus vary considerably in the way the esophagus, stomach, and gastroesophageal junction are defined. The most common definition uses the proximal limit of the gastric rugal folds as defining the gastroesophageal junction [1]. Others use the squamocolumnar junction [2], the lower end of the lower esophageal sphnicter, or the peritoneal reflection [3] to define the junction. These definitions are accepted despite evidence that they are incorrect. For example, it is well known that the squamocolumnar junction moves proximally due to glandular metaplasia of the lower esophagus in patients who have reflux [4]. The lower esophageal sphincter (LES) is commonly shortened in patients who have reflux [5]. Both the squamocolumnar junction and the LES are therefore variable points and cannot be used to define the lower end of the esophagus. The peritoneal reflection is clearly not an appropriate definition of the lower end of the esophagus. In normal patients the LES, which is approximately 5cm long, has an abdominal length that is usually about 2cm. The abdominal part of the LE5, which is part of the lower esophagus, is normally lined by peritoneum. Despite all these definitions, for most people the esophagus is usually defined as the tubal structure that changes abruptly at the gastroesophageal junction to become the saccular stomach.