Measuring Integrated Relaxation Pressure Across the Lower Esophageal Sphincter Alone in a Hiatus Hernia Reduces...

Elevated integrated relaxation pressure (IRP) on high-resolution manometry (HRM) could signify outflow obstruction, but could be artifactually elevated in the presence of a hiatus hernia (HH). We hypothesized that separate IRP measurements across the lower esophageal sphincter (LES) and crural diaphragm (CD) would differ from conventional IRP in the context of a hiatus hernia.

Esophageal tests from 467 patients were analyzed for differential IRP measurement across LES or CD separately in the presence of a HH. Patients were required to have undergone HRM and ambulatory reflux monitoring off antisecretory therapy for the investigation of esophageal symptoms presumed to be of reflux etiology to be considered for inclusion. A comparison cohort of 19 achalasia patients with HH was also analyzed. Supine IRP > 15 mmHg was considered abnormal.

Median IRP was higher across both LES and CD compared to either LES or CD alone (p < 0.001). Among 158 patients with differential LES-CD IRP measurements, conventional median IRP > 15 mmHg was seen in 11 patients (7.0%), but only in 3 patients (2.0%) across either LES or CD (p = 0.03), and only one (0.6%) across the LES (p = 0.003). Although IRP across the LES was significantly higher in achalasia compared to patients with HH (p < 0.001), IRP across the CD alone was not abnormal in both cohorts.

Differential IRP measurement in HH reduces overdiagnosis of outflow obstruction.