PD06.06. The Effect of Gastroesophageal Reflux Disease on EndoFlip Parameters: A Retrospective Cohort Study

Abstract

Benign Disease: Gastro-Esophageal Reflux and Hiatal Hernia Gastroesophageal reflux disease (GERD) is a condition often diagnosed via pH testing or endoscopy. The esophagogastric junction (EGJ) distensibility, measured by EndoFLIP, has been suggested as a potential biomarker for GERD. We aimed to evaluate whether adults with objectively confirmed GERD have higher EGJ distensibility compared to individuals without GERD A retrospective cohort study was conducted involving 86 adults (50 cases with GERD and 36 controls without GERD, confirmed negative by pH testing). GERD patients were defined as having either positive pH testing or objective evidence of GERD on endoscopy following Lyon Consensus 2.0 criteria. Patients with prior fundoplication, bariatric, or esophageal surgery were excluded from the study, as well as those diagnosed with major motility disorders, such as achalasia. Primary outcomes included the EGJ distensibility index (EGJ-DI, mm2/mmHg) and EGJ distensibility category (normal, reduced, inconclusive). Secondary outcomes included maximum EGJ opening diameter and contractility patterns. Demographics, BMI, hiatal hernia presence, and PPI use were also recorded. Statistical analyses were performed using t-tests, chi-square tests, and ANCOVA, controlling for sex. The average age of participants was 50.7±15.5 years, with cases averaging 52.8±14.2 years and controls 47.9±17.0 years (p=0.15). Gender distribution differed significantly between groups (p=0.0049), with more females in the control group (88.9%) than the case group (62.0%). Ethnicity and racial distribution were similar between groups (p=0.25 and p=0.23, respectively), with 38.4% of participants identifying as Black/African American and 40.7% identifying as Hispanic/Latino. The mean EGJ-DI was 4.3±2.0 in cases and 4.5±2.0 in controls (p=0.55), with no significant differences in EGJ distensibility categories (p=0.43) or maximum EGJ opening diameter (p=0.12). Contractility patterns also did not differ significantly between groups (p=0.10). Although 19 patients in the cohort had a hiatal hernia, the majority of these hernias were small (≤3 cm), and the presence of a hiatal hernia was not statistically different between the GERD and control groups. There was no significant difference in BMI. These findings suggest that EGJ-DI may not be a reliable indicator for distinguishing acid reflux, challenging its use as a diagnostic tool for GERD. Importantly, this study draws from a more diverse and representative patient population than is typical in the current EndoFLIP literature, enhancing the generalizability of these results. Further studies with larger sample sizes are needed to confirm these findings and explore alternative biomarkers for GERD.