Background Preoperative esophagogastroduodenoscopy (EGD) in patients undergoing bariatric surgery can help surgeons detect abnormalities in the upper gastrointestinal (UGI) tract that may require a change in surgical plan. However, the need for EGD before bariatric surgery is controversial. Objectives We aimed to determine the prevalence of UGI abnormalities and evaluate the predictive factors of abnormal findings that require a change in surgical plan or cause a delay in surgical treatment in patients undergoing bariatric surgery and develop a prediction model. Methods The medical records from January 2012 to July 2020 were retrospectively reviewed in patients who underwent EGD before bariatric surgery. The EGD findings were classified into four groups based on their effects on management. Group 1 had normal findings. Group 2 had abnormal findings that did not require a change in surgical management. Group 3 had abnormal findings that required a change in the surgical plan or caused a delay in surgical treatment. Group 4 had contraindications to surgery. Predictive factors for Groups 3 and 4 were analyzed using univariate and multivariate analyses. A model visualized as a nomogram was developed based on significant factors. Discrimination and calibration were evaluated. Results A total of 461 patient records (63.8% female) were reviewed. The mean age was 35.1 ± 11.2 years and the mean BMI was 47.7 ± 8.7 kg/m 2 . The prevalence of endoscopic findings in Groups 1, 2, 3, and 4 were 42.5%, 35.6%, 21.9%, and 0%, respectively. The most common abnormal findings were non-erosive gastritis (31.2%) followed by Helicobacter pylori infection (18.7%) and hiatal hernia (10.2%). Male sex and NSAID use were significantly associated with detection of lesions in Group 3 either on univariate or multivariate analysis, while type 2 diabetes mellitus (T2DM) was a significant protective factor on multivariate analysis. On subgroup analysis in patients ≥ 40 years old, multivariate analysis revealed age, BMI, and NSAID use were significantly associated with the detection of lesions in Group 3, while T2DM was still a significant protective factor. A nomogram to predict lesions in Group 3 for this subgroup was developed and showed good discrimination (C-statistics 0.737, 95% CI 0.721-0.752).
