Manometric study of hiatal hernia and its correlation with esophageal peristalsis.

The pathogenesis of gastroesophageal reflux disease (GERD) is considered multifactorial, but alterations of the esophagogastric junction (EGJ) and hiatal hernia play a prominent role. The correlations between hiatal hernia and the other pathogenetic factors are as yet unclear, and they need to be investigated by a methodological approach based on new anatomic and functional criteria. Our aim was to study, by stationary manometry, the relationships between small reducible hiatal hernia, identified by endoscopy, and esophageal peristalsis, in patients with and without GERD. According to the absence or presence of esophagitis (E), and the absence or presence of hiatal hernia (H), 58 subjects were divided into four groups: controls 10; H 14; E 10; and HE 24. Stationary manometry was performed by the rapid pull-through (RPT) technique, with catheter water perfused, to study the lower esophageal high pressure zone [lower esophageal sphincter (LES) and diaphragmatic crura] and the parameters of esophageal peristalsis. In patients with hiatal hernia, the various combinations of peak and/or deflection of manometric line pressure identified five EGJ profiles, only one of which reveals (by one-peak profile due to superimposed LES and diaphragmatic crura) the reducibility of the hernia. The frequency of the five profiles was calculated in the HE and H groups: a two-peak profile was significantly more prevalent in these patients, although less so in the group with esophagitis. In E patients the distal amplitude and the distal propagation of esophageal waves were significantly lower than in the other three groups (P < 0.05 vs controls and group HE; P < 0.01 vs group H). Furthermore, the distal amplitude was significantly higher in the group H than in the HE (P < 0.01). Our results show a better definition of hiatal hernia morphology, via the RPT technique, disclosing five pressure profiles. In addition, a significant link was found between small reducible hiatal hernia without GERD and wave amplitude of the distal esophagus. The amplification of peristaltic clearing may be considered the initial protective process against acid reflux; the breakdown of this mechanism may trigger the pathological sequence of GERD.