S847 Comparison of Chicago Classification v3.0 and v4.0 for Motility Disorder Diagnoses in Patients With Hiatal Hernia

Introduction: The introduction of Chicago Classification version 3.0 (CCv3) in 2014 led to increased diagnoses of esophagogastric junction outflow obstruction (EGJOO) and ineffective esophageal motility (IEM), including findings of uncertain clinical significance. In response, version 4.0 (CCv4) revised diagnostic criteria to enhance clinical relevance. Given the frequent coexistence of hiatal hernia (HH) with EGJOO and IEM, in this study we aimed to evaluate the effect of CCv4 on motility disorder diagnoses in patients with and without HH. Methods: We retrospectively reviewed patients who underwent high-resolution esophageal manometry (HREM) between January 1, 2013, and May 31, 2013, and collected clinical, endoscopic, and radiologic data. We reassessed manometry findings using both CCv3 and CCv4 and compared patients with and without HH. We performed statistical analysis using Chi-square tests, with significance set at P < 0.05. Results: Among 421 patients (75% women, mean age 53 ± 29 years, body mass index 32 ± 8 kg/m²), the most common indications for HREM were dysphagia (55%) and GERD (26%). HH was present in 149 (35%) patients. Under CCv3, EGJOO, and IEM were diagnosed in 9.3% and 24.5% of all patients, respectively. These rates significantly declined to 1.7% and 13.5% under CCv4 (both P < 0.001). In patients with HH, EGJOO diagnosis decreased from 8.9% (CCv3) to 2.2% (CCv4, P = 0.001), while IEM rates remained similar (26.2% vs 22.1%, P = 0.42). Under CCv4, patients with HH had significantly higher rates of IEM than those without HH (22.1% vs 10.5%, P = 0.001), but EGJOO rates were comparable (2.2% vs 1.5%, P = 0.27). None of the patients with HH and EGJOO required surgical intervention. Conclusion: CCv4 significantly reduced the diagnosis of EGJOO and IEM, aligning manometric findings more closely with clinical relevance. In patients with HH, EGJOO was more selectively diagnosed under CCv4, while IEM remained prevalent—likely reflecting underlying reflux pathology. These findings support CCv4’s refinement goals and underscore the importance of contextual interpretation of manometry in the presence of HH to avoid overdiagnosis and unnecessary interventions.