Hiatal hernia size affects lower esophageal sphincter function, esophageal acid exposure, and the degree of mucosal injury

BACKGROUND: Since the role of a hiatal hernia in the pathophysiology of gastroesophageal reflux disease (GERD) has not been fully elucidated, we studied the effects of hiatal hernias on the function of the lower esophageal sphincter (LES) and esophageal acid clearance. PATIENTS AND METHODS: Ninety-five consecutive patients with GERD diagnosed by 24-hour pH monitoring underwent upper gastrointestinal series (UGI), endoscopy, and esophageal manometry. Based on the presence (H+) or absence (H-) of a hiatal hernia on UGI series, they were divided into two groups: H+ (n = 51) and H- (n = 44), Then, using the size of the hiatal hernia, the H+ group was divided into three subgroups: I, H <3 cm (n = 31); II, H 3.0 to 5 cm (n = 14); and III, H >5 cm (n = 6). RESULTS: Esophageal manometry showed that patients with larger hiatal hernias (groups II and III) had a weaker and shorter LES and less effective peristalsis compared to patients with a small or no hiatal hernia. Prolonged pH monitoring showed that patients with larger hiatal hernias were exposed to more refluxed acid and had more severely abnormal acid clearance. Endoscopy showed more severe esophagitis among patients with GERD and hiatal hernia compared with GERD patients without hiatal hernia, and the degree of esophagitis was proportionate to the size of the hernia. CONCLUSIONS: Among patients with proven GERD, those with a small hiatal hernia and those with no hiatal hernia had similar abnormalities of LES function and acid clearance. In patients with larger hiatal hernias, however, the LES was shorter and weaker, the amount of reflux was greater, and acid clearance was less efficient. Consequently, the degree of esophagitis was worse in the presence of a large hiatal hernia.