Association between endoscopic pressure study integrated system (EPSIS) and high-resolution manometry

Background and study aims The endoscopic pressure study integrated system (EPSIS), a novel diagnostic tool for gastroesophageal reflux disease (GERD), allows evaluation of the anti-reflux barrier using endoscopy by monitoring the intragastric pressure (IGP) during insufflation. In this study, we evaluated the association between EPSIS results and lower esophageal sphincter (LES) function measured by high-resolution manometry (HRM) to elucidate whether EPSIS can evaluate the LES function. Patients and methods A retrospective, single-center study of patients with GERD symptoms who underwent endoscopy, pH-impedance monitoring, EPSIS, and HRM was conducted. The primary outcome was basal LES pressure and the secondary outcomes were end-respiratory LES pressure and integrated relaxation pressure (IRP). As EPSIS parameters, the following were measured: 1) pressure difference (mmHg), the difference between maximum and basal IGP; and 2) pressure gradient (mmHg/s), calculated by dividing pressure difference by the insufflating time. Pressure difference < 4.7 mmHg or pressure gradient < 0.07 mmHg/s was defined as an EPSIS GERD pattern. Results Forty-seven patients (median age: 53 years, 37 female) were analyzed. Pressure difference and pressure gradient significantly correlated with basal LES pressure (ρ = 0.29; P = 0.04 and ρ = 0.29; P = 0.04). Patients with EPSIS GERD pattern showed significantly lower basal LES pressure [13.2 (4.8–26.6) vs 25.3 (10.4–66.7) mmHg, P = 0.002], lower end-respiratory LES pressure [8.5 (1.1–15.9) vs 15.5 (1.9–43.9) mmHg, P = 0.019] and lower IRP [5.9 (1.0–12.0) vs 9.8 (1.3–17.8) mmHg, P = 0.020]. Conclusions This study showed a close association between EPSIS results and LES pressures measured by HRM. This indicates that EPSIS can evaluate the LES function during endoscopy and endorse the role of EPSIS as a diagnostic tool for GERD.