546. ESOPHAGEAL FUNCTION TESTS BEFORE AND AFTER LAPAROSCOPIC SLEEVE GASTRECTOMY FOR SEVERE OBESITY

Abstract Background Gastroesophageal reflux disease is common in patients with severe obesity. However, changes in esophageal motility and gastroesophageal reflux in patients undergoing sleeve gastrectomy have not been well-studied. In this study, we evaluated the effects of sleeve gastrectomy on esophageal function. Methods All patients undergoing laparoscopic sleeve gastrectomy (LSG) at our institution are entered into a prospectively maintained database. We queried this database to identify patients who underwent pre- and post-LSG esophageal function tests (ie, high-resolution manometry [HRM] and 24-hour pH monitoring). Post-operative was esophageal function tests done at 12 months after surgery. Results A total of 44 patients underwent LSG between Jul. 2018 and Dec. 2022, of which 11 patients underwent both pre and post-LSG esophageal function tests. The study cohort had a mean age of 65.4 years with 5 males. BMI was significantly decreased after LSG (40.0 vs. 27.4 kg/m2，p=0.004). Manometric hiatal hernia was increased post-LSG (0% vs. 45.5% [n=5/11]), though this difference did not reach statistical significance (p=0.063). Esophagogastric junction contractile integral (EGJ-CI), thoraco-abdominal pressure gradient, and distal contractile integral (DCI) were similar between the two groups (p=0.155, p=0.154, and p=0.131, respectively). Post-LSG 24-hour pH monitoring showed higher acid exposure time (0.4% vs. 11.2%, p=0.005) and DeMeester score (3.5 vs. 33.2, p=0.003). Conclusions Gastroesophageal reflux was significantly exacerbated post-LSG, although esophageal motility and EGJ pressures were preserved after LSG. This may indicate that the change in EGJ morphology and disruption of the angle of His have an important role in mechanism of LSG-related GERD.