Asymmetrical circumferential distribution of esophagogastric junctional lesions: anatomical and physiological considerations.

Several components of the gastrointestinal tract including the esophagogastric junction (EGJ) show circumferential asymmetry in the formation of pathological lesions, which is caused by the morphological and functional asymmetry of the gastrointestinal tract. Pressure in the lower esophageal sphincter (LES) is higher on the left posterior side as compared to the right anterior side, which may partly explain why Mallory-Weiss tears frequently occur on the right side wall of the EGJ. Lower LES pressure in the right anterior wall may not effectively prevent gastroesophageal reflux on this side and may be a reason why esophageal erosions in patients with reflux esophagitis, short segment Barrett's esophagus, and adenocarcinomas associated with short segment Barrett's esophagus are frequently found in the right anterior wall of the esophagus. In addition, acidic gastroesophageal reflux may also cause rupture of esophageal varices predominantly on that side. Thus, asymmetrical LES pressure may be a cause of the right anterior side predominance of diseases found in this part of the gastrointestinal tract.