Thresholds of Straight Leg Raise Maneuver During High-Resolution-Manometry

High resolution manometry (HRM) is a key test in the preoperative assessment of patients with gastro-esophageal reflux disease (GERD) who are potential candidates for antireflux surgery. The recent Lyon consensus suggested the potential usefulness of HRM in diagnosing GERD, however, sensitivity and specificity of HRM for GERD remains low (53.6% and 72.5% respectively). Among recently proposed provocative tests during manometry, a traditional maneuver (straight leg raise maneuver, SLR) appeared promising in predicting reflux. This is a multicenter study involving high-volume esophageal function laboratories around the world. Patients with suspected GERD and tested with HRM and pH-impedance will be asked to perform SLR during HRM. Intra-abdominal and intra-esophageal pressure during SLR will be recorded and compared with acid exposure time (AET) at pH-impedance. Primary aim is to determine the optimal threshold of intra-esophageal pressure augmentation during straight leg raise (SLR) maneuver that predicts pathological esophageal acid exposure time (AET). Secondary aim is to assess the diagnostic performance of HMR with SRL maneuver, calculating sensitivity, specificity, false-positive rate (FPR), false-negative rate (FNR), positive predictive value and total misclassification rate.