Manometric components of the lower esophageal double hump

Background/Aims: The lower esophageal sphincter manometry of patients with hiatal hernia often displays a double hump configuration. It seems that thi s is due to gastric herniation above the high-pressure zone of the crura. T his study examines this manometric phenomenon in patients with hiatal herni a and relates it to the lower esophageal antireflux barrier. Methods: Manom etric and 24-hour pH studies of 68 consecutive patients with suspected gast roesophageal reflux disease were analyzed to obtain information regarding t he double hump and acid reflux, Results: The findings of a manometric doubl e hump correlated well with the presence of a hiatal hernia of > 5 cm, The overall length of the sphincter complex was greater in patients with a doub le hump, but the length below the respiratory inversion point was constant. Resting pressures at the respiratory inversion point were significantly lo wer than those measured at either high-pressure zone. The location of the r espiratory inversion point was seen most commonly at the superior margin of the distal high-pressure zone. Double hump patients with a negative acid r eflux score were found to have higher pressures in the distal high-pressure zone than those patients with acid reflux. Conclusions: The two high-press ure zones comprising the manometric double hump represent the crural and mu scular components of the lower esophageal sphincter, Descriptive informatio n regarding the double hump phenomenon is given, and the importance of the crural component of the lower esophageal sphincter in preventing acid reflu x is stressed. Copyright (C) 2000 S. Karger AG, Basel.