Background: High-resolution manometry
(HRM) allows characterization of esophagogastric junction
(EGJ) morphology and identification of hiatus hernia
using novel software tools.
The main purpose of this study was to determine the impact of HRM-based EGJ and lower esophageal sphincter (LES) metrics in predicting abnormal reflux burden.
Total, upright, and supine acid exposure times (AETs) were extracted from ambulatory reflux monitoring performed off therapy in 482 patients (54.2±0.6 y, 63.3% female patients). EGJ morphology was categorized into type 1 (superimposed LES and crural diaphragm), type 2 (<3 cm separation between LES and crural diaphragm), and type 3 (≥3 cm separation). EGJ-contractile integral (EGJ-CI) and distal contractile integral (DCI) were extracted. Conventional EGJ and LES metrics, including basal and end-expiratory LES pressure, and LES length were also analyzed. Univariate and multivariate analyses were performed to determine the value of HRM parameters in predicting abnormal esophageal reflux burden.
Type 1 EGJ was noted in 298 (61.8%), type 2 in 125 (25.9%), and type 3 in 59 (12.2%); EGJ-CI and mean DCI were lower with abnormal EGJ morphology. Mean AET, and proportions with abnormal AET increased as EGJ morphology became progressively disrupted (P
<0.0001 across groups); low EGJ-CI was additive in predicting abnormal AET. All HRM parameters assessed (EGJ morphology, EGJ-CI, and DCI) were independent predictors for abnormal AET (P
≤0.02). Conventional LES and EGJ metrics were also associated with abnormal reflux burden, but intra-abdominal LES length, and hiatus hernia
size did not independently predict total AET.
HRM-based EGJ morphology and EGJ barrier assessment independently predict esophageal reflux burden.