Diagnostic accuracy of symptoms compared to endoscopy, biopsy and bile reflux index in detecting reflux-related abnormalities at one year after OAGB.

Background: The diagnostic accuracy of clinical symptoms in detecting reflux-related abnormalities after One anastomosis gastric Bypass (OAGB) remains unclear. This study evaluates the diagnostic performance of reflux symptoms compared to upper endoscopy (UE), biopsy, and bile reflux index (BRI) findings at one-year post-OAGB.

Methods: A retrospective analysis was conducted on 150 consecutive patients who underwent OAGB between November 2017 and June 2018 and had no preoperative reflux symptoms. At one year postoperatively, patients completed the Gastroesophageal Reflux Disease Questionnaire (GerdQ) for symptom assessment. UE, histopathological biopsy, and BRI calculations were performed. The diagnostic accuracy of symptoms was evaluated against UE, biopsy, and BRI findings using sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and the area under the receiver operating characteristic curve (AUROC).

Results: Among 144 patients analyzed, 25.7% reported GERD symptoms, while abnormal findings were observed in 62.5% (UE), 65.3% (biopsy), and 19.4% (BRI). Symptoms demonstrated high specificity and PPV (100%) in predicting UE and biopsy abnormalities but had low sensitivity (41.1% for UE, 39.4% for biopsy) and moderate NPVs (50.5% and 46.7%, respectively), indicating a risk of false negatives. The AUROC values were 0.71 (UE) and 0.70 (biopsy), reflecting moderate diagnostic discrimination. For BRI, symptom presence had 88.8% specificity and 64.9% PPV, but symptom absence correlated with high sensitivity (85.7%) and excellent NPV (96.3%), yielding an AUC of 0.87. Notably, 95.8% of symptomatic patients with abnormal BRI exhibited anastomotic site abnormalities, and 95.7% of patients with anastomotic pathology had concurrent distal esophageal and gastric pouch abnormalities.

Conclusions: Symptoms may serve as a predictor of reflux-related abnormalities on UE or biopsy, but their absence is unreliable in ruling out such abnormalities. While symptoms effectively forecast abnormal BRI in high-prevalence settings, their diagnostic utility remains limited. Further research is warranted to assess long-term diagnostic accuracy and refine post-OAGB reflux assessment protocols.