RESUMO
BACKGROUND: Etiology of gastro-esophageal reflux disease (GERD) is multifactorial, but incompetence of the esophago-gastric junction (EGJ) appears to be of crucial importance. Established manometric parameters for assessment of EGJ barrier function are sub-optimal, potentially because they reflect only a very brief (up to 30 seconds), not necessarily representative period. This prospective, case-control study tested the performance of novel, high-resolution manometry (HRM) parameters of EGJ function in the assessment of GERD. METHODS: Patients with reflux symptoms and healthy controls (HC) underwent standard HRM and 24-hour pH±impedance measurements. EGJ morphology, lower esophageal sphincter pressure integral (LES-PI), EGJ contractile integral (EGJ-CI) were compared with total-EGJ-CI, a novel parameter summarizing EGJ barrier function during the entire HRM protocol. Esophageal acid exposure ≥4.2%/24 h (A-Reflux-pos) or ≥73 reflux episodes in 24 hours (V-Reflux-pos) were considered pathological. KEY RESULTS: Sixty five HC and 452 patients completed HRM, 380 (84%) patients underwent ambulatory reflux-monitoring. LES-PI, EGJ-CI and total-EGJ-CI correlated with EGJ morphology subtypes (all P<.00001). Only total-EGJ-CI was consistently lower in A-Reflux-pos and V-Reflux-pos subjects compared with HC and patients without GERD. Total-EGJ-CI was also the single best parameter for prediction of pathological reflux (optimal cut-off 47 mmHg cm, AUC 0.746, P<.0001). This cut-off value, approximately 1 SD below the mean normal value, showed modest sensitivity 54% and positive predictive value 46%, but good specificity 85% and negative predictive value 89% for GERD diagnosis. CONCLUSION & INFERENCES: Total EGJ-CI, a new metric that summarizes EGJ contractility over time, allows an improved assessment of EGJ barrier function. Pathological reflux is unlikely if this metric is within the upper two-thirds of the normal range.
