S913 EndoFlip Distensibility Index: A Valuable Diagnostic Tool for Differentiating Erosive Esophagitis and Non-Erosive Reflux Disease

Introduction: Inappropriate relaxation of the lower esophageal sphincter allows retrograde flow of gastric acid into the esophagus, thereby inducing reflux in gastroesophageal reflux disease (GERD). A pilot study conducted by our team found statistically significant data suggesting that the endoluminal functional lumen imaging probe (EndoFLIP) esophagogastric junction distensibility index (EGJ-DI) may serve as a strong diagnostic predictor of reflux disease. We aim to further evaluate the utility of EndoFLIP in distinguishing between patients with erosive esophagitis and those with non-erosive reflux disease with a larger sample size. Methods: We retrospectively analyzed 158 patients with reflux disease who underwent EndoFlip. EGJ-DI at balloon volumes of 40 mL, 50 mL, 60 mL, and 70 mL were measured. Statistical analysis was performed using a one-tailed t test with paired variance. Results: Among the 158 patients with reflux disease, 73 patients had erosive esophagitis and 85 patients had non-erosive reflux disease. Patients with erosive esophagitis had an average distensibility index of 5.07 at 40 mL, 5.44 at 50 mL, 5.74 at 60 mL and 5.33 at 70 mL. In patients with non-erosive reflux disease, an average distensibility index (DI) of 3.73 at 40 mL, 4.13 at 50 mL, 4.78 at 60 mL and 4.02 at 70 mL was observed. The difference in average distensibility index was statistically significant between the 2 groups for all balloon volumes with P-value of 0.032 (DI 40), 0.011 (DI 50), 0.036 (DI 60), and 0.004 (DI 70). Conclusion: Our study further demonstrates that EndoFLIP can effectively differentiate between erosive esophagitis and non-erosive reflux disease by measuring EGJ-DI. The differences were statistically significant for all distensibility indexes. These results suggest that EndoFLIP is a useful diagnostic tool in regards to reflux disease and supports its use in clinical practice.