Abstract
Although endoscopy and pH monitoring are gold standards for GERD diagnosis, manometry provides additional insight into esophagogastric junction (EGJ) function. Several manometric parameters have been explored as GERD predictors, but a comprehensive synthesis is lacking. This systematic review aims to evaluate their reported diagnostic performance. A systematic search of MEDLINE, EMBASE, and EBSCO (1970–2024) included studies comparing manometric parameters in GERD and non-GERD patients. Statistical differences and diagnostic performance of these metrics (with pH-monitoring or endoscopy as reference standards) were extracted. Descriptive analysis was performed, and data were synthesized into Forest plots, where applicable. Of 1,821 screened, 60 were included (51 cross-sectional, 9 cohort [8 prospective, 1 retrospective], 10,973 patients). Thresholds for competent lower esophageal sphincter (LES) included overall length 2-3 cm (sensitivity [SE] 2.6-64%, specificity [SP] 81.5-98.9%) and abdominal length 1 cm (SE 4.5-70%, SP 45-98.4%). LES pressure (LESP) was significantly different in 16/40 studies (SE of 5.5-70%, SP 50-98%). EGJ contractile integral (EGJ-CI) and LESP integral (LESPI) were significant in 14/17 and 3/4 studies, respectively. EGJ-CI showed AUC 0.576-0.814 (SE: 57.8-89%, SP: 36.3-81.7%). LESPI had two cutoffs, 400 and 100 mmHg∙s∙cm (SE 79% and 34.9%, SP 54% and 79.7%, respectively). EGJ morphology (Chicago v3.0 and 2017 International Consensus) was significantly different in 3/9 and 6/7 studies, respectively; Akimoto classification (1 study) also showed significance. Trans-abdominal pressure gradient, though lacking standardization, was significant in 5/5 studies. Among novel metrics, total EGJ-CI (1 study, AUC 0.746) and straight leg raise maneuver (2 studies, AUC 0.78 and 0.84) showed the best diagnostic performance. No single manometric EGJ metric reliably predicted GERD, but some of them show potential in assessing EGJ competence. A comprehensive HRM metric for EGJ competence is needed. This could potentially guide treatment decisions as endoscopic and surgical options for restoring competence expand.