Novel 3D high-resolution manometry metrics for quantifying esophagogastric junction contractility.

BACKGROUND: The esophagogastric junction (EGJ) is a complex sphincter composed of both the crural diaphragm (CD) and lower esophageal sphincter (LES). Three dimensional high-resolution manometry (3D-HRM) provides a dynamic 360° representation of EGJ pressure in which the CD has a distinct pressure signature. We aimed to develop 3D-HRM metrics to: (i) quantify the vigor of CD contractility, (ii) best eliminate the CD contribution and thereby isolate the LES component of EGJ contractility, and (iii) compare these metrics with conventional HRM metric of EGJ contractility.
METHODS: Twenty healthy subjects underwent 3D-HRM studies. Two novel 3D-HRM EGJ metrics, 3D-DHA , and 3D-LES pressure (3D-LESP) were devised and calculated to best approximate the CD and LES components of the composite EGJ pressure topography. These values were then compared to conventional HRM metrics of EGJ contractility, the EGJ contractile integral (EGJ-CI), inspiratory EGJ pressure and expiratory EGJ pressure. KEY
RESULTS: Mean 3D-DHA correlated most strongly with EGJ-CI (r=.82, P<.001), while the 3D-LESP correlated most strongly with inspiratory EGJ pressure (r=.91 P<.001) and expiratory EGJ pressure (r=.85, P<.001). CONCLUSIONS & INFERENCES: We devised novel 3D-HRM metrics to quantify the CD (3D-DHA ) and LES (3D-LESP) elements of EGJ contractility. Both measures correlated strongly with conventional HRM metrics of EGJ contractility. The 3D-DHA , in particular, correlated strongly with the EGJ-CI suggesting that both are largely determined by CD contractility. It is hoped that future studies will show these new metrics useful in quantifying elements of the antireflux barrier in mechanistically defined subsets of gastro-esophageal reflux disease (GERD) patients.