Predicting common bile duct stones by non-invasive parameters

Common bile duct (CBD) stone affect about 10% of patients with symptomatic cholelithiasis. The American Society for Gastrointestinal Endoscopy (ASGE) published a strategy in 2010 for managing patients with suspected choledocholithiasis. This study aimed to assess the performance of different clinical parameters in predicting CBD stones. A total of 344 patients suspected to suffer from CBD stone and referred to endoscopic ultrasound (EUS) were included. Parameters were collected and their prediction power for CBD stones was assessed. One hundred and sixty-seven patients without CBD stone according to EUS (group A) were compared to 177 patients with CBD stones (group B). Several predictive factors for CBD stone were identified on univariate analysis. In multivariate regression analysis, CBD width by US (OR = 1.224, 95% CI: 1.073–1.359; P = 0.0026), age (OR = 1.023, 95% CI: 1.011–1.035; P = 0.0002) and gamma glutamyl transferase (GGT) level (OR = 1.001, 95% CI: 1.000–1.002; P = 0.0018) were significantly correlated with CBD stone, with receiver operator characteristics (ROC) of 0.7259. We generated a diagnostic equation [age (yr) × 0.1 + CBD width (mm) by US × 1 + GGT (U/L) × 0.005] to predict CBD stone with ROC of 0.7287. We suggest this score as a very strong predictor for CBD stones, and to reduce the strength of total bilirubin and transaminases as predictors.