The role of esophageal motility and hiatal hernia in esophageal exposure to acid

Background: Thee pathogenesis of gastroesophageal reflux disease (GERD) is multifactorial. This study evaluates the relationship between esophageal exposure to acid, the presence or absence of a hiatal hernia, and manometric indicators of esophageal motility. Methods: A total of 51 patients with foregut symptoms were evaluated with upper gastrointestinal series or endoscopy, 24-h pH testing, and esophageal manometry. The DeMeester score was used to distinguish patients with physiologic reflux (DeMeester score < 14.72) from patients with pathologic reflux (DeMeester score > 14.72). Results: Patients with physiologic reflux had fewer hypotensive contractions and a smaller percentage of uncoordinated and hypotensive contractions combined, as compared to patients with pathologic reflux. The amplitude of distal esophageal contractions was greater in patients with physiologic reflux. Also, patients with a hiatal hernia had a higher incidence of pathologic reflux, regardless of the lower esophageal sphincter pressure. Conclusion: Patients with pathologic reflux have abnormal acid exposure associated with pump failure of the esophagus and/or a mechanical defect of the cardia associated with a hiatal hernia.