T1973 Proton Pump Inhibitor Treatment Ameliorates Dilated Intercellular Space, Decrease and Dislocalization of Esophageal Mucosal Tight Junction Proteins in a Rat Chronic Acid Reflux Esophagitis Model

Abstract

BACKGROUND & AIMS: Fundoplication attempts to restore the anatomy of the antireflux barrier, but its effects on the mechanical properties of the esophagogastric junction (EGJ) are still unclear. The aim of this study was to compare the geometry and pressure dynamics of the EGJ in healthy controls and postfundoplication (PF) patients during distension challenges. METHODS: Ten healthy controls (2M, 23-50 yr) and 10 asymptomatic PF patients (2M, 42-68 yr) were evaluated with a functional luminal imaging probe (FLIP) using impedance planimetry technology. The probe was placed transnasally at the EGJ based on manometric landmarks and fluoroscopic confirmation. Six cross sectional areas (CSA) were measured at 4-mm intervals inside a cylindrical saline-filled bag, together with simultaneous measurement of intrabag pressure. EGJ distensibility was assessed during both the inter-deglutitive and deglutitive-relaxation periods by analyzing the changes in CSA and intrabag pressure during volume-controlled distensions of 30, 40, 50 and 60 mL. RESULTS: In controls and PF patients, the EGJ formed a funnel shape that open proximally and constricted chiefly in its mid-section. The CSA of maximal constriction at mid-EGJ was similar in both groups at bag volumes ranging from 30-50 mL during inter-deglutitive and deglutitive-relaxation periods (Table). A 60 mL bag distended the EGJ to a much larger CSA in healthy controls than PF patients during the deglutitive-relaxation period (Table). Despite having similar CSA, the augmentation in intrabag pressure related to successive volume distensions (3060mL) was amplified in PF patients throughout both the inter-deglutitive (controls, 21.8 to 32.6 cmH2O; PF, 24.1 to 39.7 cmH2O, p<0.002) and the deglutitive-relaxation periods (controls, 18.3 to 25.2 cmH2O; PF, 17.0 to 31.0 cmH2O, p<0.02).CONCLUSION: Fundoplication appears to restore the inter-deglutitive and deglutitive-relaxation EGJ geometry to a level seen in controls. However, this return to normal geometry is associated with a decrease in compliance evidenced by the higher pressure at each distention volume.