High-resolution Manometry can Characterize Esophagogastric Junction Morphology and Predict Esophageal Reflux Burden

Background: High-resolution manometry (HRM) allows characterization of esophagogastric junction (EGJ) morphology and identification of hiatus hernia using novel software tools. Aim: 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. Methods: 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. Results: 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. Conclusions: HRM-based EGJ morphology and EGJ barrier assessment independently predict esophageal reflux burden.