Impaired air-liquid settling during swallowing in gastroesophageal reflux disease. A digital videofluoroscopic study

We hypothesize that the surface of the zone of air-liquid mixture in the esophagus after swallowing is the result of the esophageal gastric junction (EGJ) function or dysfunction. The aim of this study was to quantify the air-liquid components of the bolus in the esophagus and across the EGJ by means of digital videofluoroscopy sequences recorded in patients with gastroesophageal reflux disease (GERD). The patients were allocated to a Normo or a Hypo group, according to basal lower esophageal sphincter (LES) pressure. Two types of analysis were undertaken from the video sequences. For static analysis, maximal opening diameter of the LES and surfaces of air, air-barium mixture, and barium suspension were measured on two images extracted from each sequence. For dynamic analysis, transit times across the EGJ of the total bolus, air, mixture, and barium suspension were evaluated on a video sequence. For static analysis, the maximal opening diameter of the LES, air, and mixture surfaces were higher in the Hypo group. For dynamic analysis, transit time of total bolus, air, and mixture were longer in the Hypo group. The increase in mixture can be attributed to a defect in settling of both air and liquid phases in the esophagus in patients with low LES pressure and/or esophageal hypotonicity. Thus, these evaluations should provide information on the passage modalities of the bolus in esophagus and across the EGJ to assess differential diagnosis of GERD and hence to better select the most appropriate antireflux surgical procedure.