Endoscopic retrograde cholangiopancreatography for suspected choledocholithiasis: From guidelines to clinical practice.

AIM To study the practical applicability of the American Society for Gastrointestinal Endoscopy guidelines in suspected cases of choledocholithiasis. METHODS This was a retrospective single center study, covering a 4-year period, from January 2010 to December 2013. All patients who underwent endoscopic retrograde cholangiopancreatography (ERCP) for suspected choledocholithiasis were included. Based on the presence or absence of predictors of choledocholithiasis (clinical ascending cholangitis, common bile duct (CBD) stones on ultrasonography (US), total bilirubin > 4 mg/dL, dilated CBD on US, total bilirubin 1.8-4 mg/dL, abnormal liver function test, age > 55 years and gallstone pancreatitis), patients were stratified in low, intermediate or high risk for choledocholithiasis. For each predictor and risk group we used the χ(2) to evaluate the statistical associations with the presence of choledocolithiasis at ERCP. Statistical analysis was performed using SPSS version 21.0. A P value of less than 0.05 was considered statistically significant. RESULTS A total of 268 ERCPs were performed for suspected choledocholithiasis. Except for gallstone pancreatitis (P = 0.063), all other predictors of choledocholitiasis (clinical ascending cholangitis, P = 0.001; CBD stones on US, P ≤ 0.001; total bilirubin > 4 mg/dL, P = 0.035; total bilirubin 1.8-4 mg/dL, P = 0.001; dilated CBD on US, P ≤ 0.001; abnormal liver function test, P = 0.012; age > 55 years, P = 0.002) showed a statistically significant association with the presence of choledocholithiasis at ERCP. Approximately four fifths of patients in the high risk group (79.8%, 154/193 patients) had confirmed choledocholithiasis on ERCP, vs 34.2% (25/73 patients) and 0 (0/2 patients) in the intermediate and low risk groups, respectively. The definition of "high risk group" had a sensitivity of 86%, positive predictive value 79.8% and specificity 56.2% for the presence of choledocholithiasis at ERCP. CONCLUSION The guidelines should be considered to optimize patients' selection for ERCP. For high risk patients specificity is still low, meaning that some patients perform ERCP unnecessarily.