Trans-esophagogastric junction pressure gradients during straight leg raise maneuver on high-resolution manometry associate with large hiatus hernias

Background: Straight leg raise (SLR) while supine increases intra-abdominal pressure. We hypothesized that elevations in intra-abdominal pressure would transmit into the thoracic cavity if the esophagogastric junction (EGJ) was disrupted.

Methods: Consecutive patients undergoing esophageal HRM were included if they had adequate SLR (hip flexion with knees extended for ≥ 5 seconds while supine). EGJ morphology was subtyped based on lower esophageal sphincter (LES) and crural diaphragm (CD) location (type 1: LES and CD overlap; type 2: separation of < 3 cm; type 3: separation of ≥ 3 cm). EGJ tone was assessed using EGJ contractile integral (EGJ-CI). HRM studies were analyzed according to Chicago Classification v3.0. Mean and peak intra-thoracic and abdominal pressures were measured at baseline and during SLR using on-screen software tools. Trans-EGJ gradients were compared, and pressure gradient < 1 mmHg denoted the equalization of pressures.

Key results: Of 430 patients, 248 (57.5 ± 0.9 years, 69.4% F) completed SLR. EGJ morphology was type 1 in 122 (49.2%), type 2 in 56 (22.6%) and type 3 in 40 (16.1%). In types 1 and 2 EGJ, neither the mean nor peak trans-EGJ pressure gradient changed with SLR (P ≥ .17 for each). In contrast, in type 3 EGJ, peak pressure gradient decreased significantly following SLR (3.5 ± 1.8 mmHg vs. -8.6 ± 4.8 mmHg, P = .01). More type 3 EGJ patients equalized peak (65%) pressures across EGJ compared with types 1 and 2 (27%, P < .001).

Conclusions and inferences: The evaluation of intra-abdominal and intra-thoracic pressures with SLR during esophageal HRM can provide evidence of physiological disruption of the EGJ barrier.