Saliva transit from the oral cavity to the esophagus in GERD

Background/Aims: Normal esophageal acid clearance depends on the neutralization of acid by swallowed saliva, as well as on esophageal peristalsis. This study therefore aimed to investigate the association between saliva production and transport from the oral cavity to the esophagus and developing gastroesophageal reflux disease (GERD) Methodology: Twenty-eight consecutive patients with GERD symptoms by gastroesophageal reflux self-report questionnaires and 13 healthy volunteers were recruited in the study. After intravenous administration of Tc-99m-pertechnetate, anterior sequential imaging was performed every minute for 40 minutes. At 20 minutes after injection of radionuclide, a lemon candy was administered intra-orally to stimulate salivary secretion. Regions of interest (ROI) were selected on the individual oral cavity, the pharynx, and the upper esophagus and time activity curves were drawn for each of these. A time-activity curve in each ROI was subjectively graded, as zero to two-point. The sum of scores in 3 ROIs was considered as a saliva transit total score. Results: The mean transit score of the oral cavity did not differ significantly between GERD patients and healthy volunteers (1.38 vs. 1.61), whereas significantly lower transit scores of pharynx and upper esophagus were found in GERD patients. A 0-point saliva transit score of pharynx and upper esophagus was significantly more frequently detected in GERD patients than in healthy volunteers. Conclusions: This new modification of saliva scintigraphy is able to evaluate the esophageal motility simply, without a test meal, and to detect impaired saliva transit between pharynx and upper esophagus in GERD patients non-invasively.