New insights into esophagogastric junction physiology

Abstract

The studies presented in this thesis have reported on the elicitation of transient lower esophageal sphincter relaxations (TLESRs) in health, gastroesophageal reflux disease (GERD) and postfundoplication. The relationship between the esophageal acid exposure time and the underlying manometric motor mechanisms, especially TLESRs, in non-hernia patients with GERD is examined. Also the effect of fundoplication on esophageal motility, bolus transit across the esophagogastric junction (EGJ) and intragastric distribution has been evaluated. The studies give new insights into the origin of postoperative dysphagia, odynophagia and dyspepsia. Furthermore, the role of the proximal stomach and the pressure gradient across the EGJ on acid reflux during TLESRs has been assessed with new technical modalities combining three dimensional (3D) ultrasonic imaging, high-resolution topographic manometer and pH-metry. This thesis provides new insights into EGJ physiology, especially on the role of proximal stomach in TLESR eliciation and on the role of the EGJ pressure gradient on gastroesophageal reflux during a TLESR. In addition, the effect of fundoplication on esophageal and EGJ motility, intragastric distribution, and EGJ transit efficacy has been evaluated. It is now apparent that an altered intragastric distribution plays a pivotal role in the genesis of postfundoplication dyspepsia. Changes in fundic and EGJ anatomy with fundoplication lead to a different pressure profile across the EGJ thereby preventing esophageal acid reflux during a TLESR and limiting EGJ transit which relates to postoperative dysphagia.