Role of diaphragmatic crura and lower esophageal sphincter in gastroesophageal reflux disease: manometric and pH-metric study of small hiatal hernia.

The rapid pull-through (RPT) technique during esophageal manometry helps to identify various pressure profiles of hiatal hernia (HH), based on the presence of two high pressure zones: the diaphragmatic crura (DC) and the lower esophageal sphincter (LES). Our aim was to correlate different HH profiles with frequency of reflux episodes in patients with gastroesophageal reflux disease (GERD). Seventy-eight patients with GERD and HH underwent esophageal manometry with RPT and were grouped according to the prevalent pressure profile of HH. Twenty-four-hour pH-metry served to quantify traditional (TR) and nontraditional refluxes (drop of 1 pH unit with pH > 4 or pH < 4 and time < 5 sec) (NTR) during total, upright, and recumbent periods. The group with a prevalent "flat" HH profile, representing LES and DC impairment, had significantly more TRs in total time of reflux (P < 0.01) and in recumbent and upright periods (P < 0.05) compared to the group with a prevalence of the two pressure peaks, corresponding to LES and DC efficiency. However, the group with the flat profile had significantly more NTRs + TRs than the group with pressure peaks in total time (P < 0.01) and recumbent position (P < 0.001) but not in the upright position. Hiatal hernia predisposes to GERD, but only the associated impairment of the LES and diaphragmatic crura pressures represents a condition of high risk for gastroesophageal reflux events.