Esophagogastric junction morphology and contractile integral on high-resolution manometry in asymptomatic healthy volunteers: An international multicenter study

Background: Esophagogastric junction contractile integral (EGJ-CI) and EGJ morphology are high-resolution manometry (HRM) metrics that assess EGJ barrier function. Normative data standardized across world regions and HRM manufacturers are limited. Methods: Our aim was to determine normative EGJ metrics in a large international cohort of healthy volunteers undergoing HRM (Medtronic, Laborie, and Diversatek software) acquired from 16 countries in four world regions. EGJ-CI was calculated by the same two investigators using a distal contractile integral-like measurement across the EGJ for three respiratory cycles and corrected for respiration (mm Hg cm), using manufacturer-specific software tools. EGJ morphology was designated according to Chicago Classification v3.0. Median EGJ-CI values were calculated across age, genders, HRM systems, and regions. Results: Of 484 studies (28.0 years, 56.2% F, 60.7% Medtronic studies, 26.0% Laborie, and 13.2% Diversatek), EGJ morphology was type 1 in 97.1%. Median EGJ-CI was similar between Medtronic (37.0 mm Hg cm, IQR 23.6-53.7 mm Hg cm) and Diversatek (34.9 mm Hg cm, IQR 22.1-56.1 mm Hg cm, P = 0.87), but was significantly higher using Laborie equipment (56.5 mm Hg cm, IQR 35.0-75.3 mm Hg cm, P < 0.001). 5^th percentile EGJ-CI values ranged from 6.9 to 12.1 mm Hg cm. EGJ-CI values were consistent across world regions, but different between manufacturers even within the same world region (P ≤ 0.001). Within Medtronic studies, EGJ-CI and basal LESP were similar in younger and older individuals (P ≥ 0.3) but higher in women (P < 0.001). Conclusions: EGJ morphology is predominantly type 1 in healthy adults. EGJ-CI varies widely in health, with significant gender influence, but is consistent within each HRM system. Manufacturer-specific normative values should be utilized for clinical HRM interpretation.