The esophagogastric junction (EGJ) is comprised of both the intrinsic lower esophageal sphincter (LES) and extrinsic crural diaphragm (CD) such that intraluminal pressure represents a composite of the two. With type I hiatal hernias there is weakening of the pharyngoesophageal ligament attaching the esophagus to the CD such that the distal esophagus, including the LES, becomes displaced cephalad. High-resolution manometry (HRM), can accurately detect an axial hiatal hernia as confirmed by studies comparing HRM to barium esophagram, upper endoscopy, or intraoperative findings. In HRM studies, hiatus hernia becomes evident by a spatial separation between the pressure signature of the LES and that of the CD; the operative confirmation of hiatus hernia correlates with this separation exceeding 1 cm. With LES-CD separation of <2 cm the HRM pressure signatures of the two overlap, but as the LES-CD separation increases beyond that the two become completely separate. The other progression noted in HRM studies is in the location of the respiratory inversion point (RIP), the axial location at which the inspiratory change in pressure transitions from an inspiratory increase, characteristic of intra-abdominal recordings to an inspiratory decrease, characteristic of intrathoracic recordings. In the normal state and with small hiatal hernias, the location of the RIP correlates with where the CD impinges on the esophagus at inspiration. However, with larger hernias the RIP can localize with either the CD or the LES reflective of whether or not the CD has become incompetent, presumably a result of hiatal dilatation. Consequently, there are three distinct EGJ pressure morphologies in HRM: (I) normal with minimal LES-CD separation, (II) hiatus hernia with LES-CD separation >1 cm and the RIP localized at the CD, and (III) hiatus hernia with LES-CD separation >1 cm and the RIP localized at the LES.
- Gastroesophageal reflux disease (GERD)
- Hiatal hernia
- High-resolution manometry (HRM)
ASJC Scopus subject areas