The Usefulness of the Measurement of Esophagogastric Junction Distensibility by EndoFLIP in the Diagnosis of Gastroesophageal Reflux Disease

BACKGROUND/AIMS: Increased esophagogastric junction (EGJ) relaxation is the most important mechanism involved in gastroesophageal reflux disease (GERD). An endoscopic functional luminal imaging probe (EndoFLIP(Ⓡ)) is a device used to quantify EGJ distensibility in routine endoscopy. The aim of the current study was to assess the usefulness of EndoFLIP(Ⓡ) for the diagnosis of GERD compared to normal controls. METHODS: We analyzed EndoFLIP(Ⓡ) data from 204 patients with erosive reflux disease (ERD), 310 patients with nonerosive reflux disease (NERD), and 277 normal subjects. EndoFLIP(Ⓡ) uses impedance planimetry to measure 16 cross-sectional areas (CSAs) in conjunction with the corresponding intrabag pressure within a 4.6 cm cylindrical segment of a fluid-filled bag. The EGJ distensibility was assessed using 40 mL volume-controlled distensions. RESULTS: The mean distensibility index values were 13.98 mm(2)/mm Hg in ERD patients, 11.42 mm(2)/mm Hg in NERD patients, and 9.1 mm(2)/mm Hg in normal subjects. There were significant differences in EGJ distensibility among the three groups (p<0.001). In addition, the CSAs were significantly higher in the ERD (291.03±160.77 mm(2)) and NERD groups (285.87±155.47 mm(2)) than in the control group (249.78±144.76 mm(2), p=0.004). We determined the distensibility index cutoff value of EGJ as 10.95 for the diagnosis of GERD by receiver operating characteristic curve analysis. CONCLUSIONS: The EGJ distensibilities of GERD patients were higher than those of normal subjects, regardless of the presence of reflux esophagitis. Thus, the measurement of EGJ distensibility using the EndoFLIP(Ⓡ) system could be useful in the diagnosis of GERD.