Changes in endoscopic pressure study integrated system (EPSIS) parameters after antireflux surgery and their association with postoperative clinical outcomes.

BACKGROUND: Objective functional assessment of the antireflux barrier after antireflux surgery (ARS) remains limited. The endoscopic pressure study integrated system (EPSIS) enables pressure-based evaluation of antireflux function during endoscopic insufflation; however, changes in EPSIS parameters after ARS and their association with postoperative clinical outcomes remain unknown. METHODS: This retrospective single-center study included consecutive patients who underwent primary ARS with available EPSIS measurements. EPSIS parameters, including maximum intragastric pressure (IGPmax), intragastric pressure gradient (IGP gradient), and insufflation time, were evaluated before and after surgery. Postoperative clinical outcomes were classified as optimal or suboptimal based on symptom improvement and changes in medical therapy. Associations between EPSIS parameters and clinical outcomes were analyzed using both continuous and threshold-based approaches. RESULTS: A total of 49 patients were included, with paired preoperative and postoperative EPSIS measurements available in 46 patients. IGPmax increased significantly after ARS (P < 0.001), as did the IGP gradient (P < 0.001), whereas insufflation time did not change significantly. Postoperative IGPmax and its perioperative change (ΔIGPmax) were significantly higher in patients with optimal outcomes than in those with suboptimal outcomes. In contrast, neither postoperative IGP gradient nor its change was associated with postoperative clinical outcomes. Threshold-based analyses showed a significant increase in the proportion of patients achieving predefined IGPmax thresholds after ARS, with a trend toward lower threshold attainment in patients with suboptimal outcomes. CONCLUSIONS: ARS predominantly affected pressure-related EPSIS parameters, with IGPmax showing a consistent association with postoperative clinical outcomes. IGPmax appears to reflect functional reinforcement of the surgically reconstructed antireflux barrier and may serve as a useful functional marker for postoperative assessment following ARS.