Straight leg raise metrics on high‐resolution manometry associate with esophageal reflux burden

Abstract

Straight leg raise (SLR) is a provocative maneuver that assesses esophagogastric junction (EGJ) barrier function during high-resolution manometry (HRM). We evaluated the value of SLR in symptomatic reflux patients undergoing ambulatory reflux monitoring. Adult patients being evaluated for reflux symptoms with esophageal physiologic testing off antisecretory therapy over a 12month period were studied. Demographics, clinical presentation, HRM studies, and reflux monitoring studies were analyzed. Intra-abdominal and intra-esophageal pressures were extracted at baseline and during SLR from HRM studies. Acid exposure time (AET) was derived from reflux monitoring studies, and EGJ morphology and tone from HRM studies. SLR pressure metrics predicting abnormal AET were evaluated. Of 122 patients, 70 (57.4%) had ≥50% peak intra-abdominal pressure increase during SLR (58.0±1.4years, 75.7% female). Peak intra-esophageal pressure gradient between baseline and SLR predicted pathologic AET when ≥100% (AUC 0.78, sensitivity 71%, specificity 75%, P<.001), seen in 60.7% with AET>6%, but only 23.7% with AET<4% (P=.01). Peak intra-esophageal pressure gradient ≥100% was most discriminative in identifying abnormal acid burden in type 1 EGJ morphology (P=.005) but trended toward significance in type 2 and type 3 morphology (P=.1). Normal and abnormal EGJ contractile integral did not associate with peak intra-esophageal pressure gradient either collectively or when subdivided by EGJ morphology (P≥.2). Analysis of intra-esophageal pressure gradients during SLR, a simple HRM maneuver, may augment evaluation of symptomatic GERD, and provide adjunctive evidence supporting GERD.