Biochemical and ultrasound parameters may help predict the need for therapeutic endoscopic retrograde cholangiopancreatography (ERCP) in patients with a firm clinical and biochemical suspicion for choledocholithiasis

Background: Prediction of the need for therapeutic endoscopic retrograde cholangiopancreatography (ERCP) in patients with suspected choledocholithiasis (CDL) remains a challenging task. Aims: We aimed to evaluate the predictive value of biochemical and ultrasound parameters and to create a corresponding model for prediction of the need for therapeutic ERCP. Methods: 203 consecutive patients referred to our center due to a firm clinical and/or biochemical suspicion for CDL. All patients underwent ERCP. Biochemical and ultrasound variables were analyzed. Results: The sample was divided into testing group (103; 50.7%) and validation group (100; 49.3%) which did not differ in their baseline characteristics. Elevated gamma glutamil transaminase (GGT), common bile duct (CBD) diameter and presence of hyperechoic structures in CBD were found to be significant predictors for presence of CBD stones on ERCP (p<0.05) in the testing group. We used these variables to construct a predictive model for the presence of CBD stones on ERCP. The model was tested on a second, validation group of patients using ROC analysis with the area under the ROC curve of 0.81 (%95 CI=0.75-0.86; p<0.001). We identified a threshold (0.86) above which, patients had a high probability (93.1%) for the need for interventional ERCP. Conclusion: Our predictive model may help predict the need for therapeutic ERCP in patients with a suspicion for choledocholithiasis. (C) 2011 European Federation of Internal Medicine. Published by Elsevier B.V. All rights reserved.