# Endoscopic Ultrasound and Endoscopic Retrograde Cholangiopancreatography for Bile Duct Stones—Avoiding the Avoidable

## TL;DR

This study shows that nearly half of high-risk patients for bile duct stones don't actually have them, suggesting that using endoscopic ultrasound and a new scoring system can help avoid unnecessary procedures.

## Contribution

The study introduces a new predictive score based on EUS findings to better identify patients who truly need ERCP, reducing unnecessary procedures.

## Key findings

- EUS identified stones in only 53.5% of high-risk patients, with 46.4% showing spontaneous clearance.
- A three-component predictive score achieved 85.7% sensitivity and 59.0% specificity for identifying CBD stones.
- Acute pancreatitis, cholangitis, and EUS-measured CBD diameter were significant predictors of retained stones.

## Abstract

Background: Endoscopic retrograde cholangiopancreatography (ERCP) is the primary treatment option for choledocholithiasis. However, this procedure carries an inherent non-negligible risk of complications, requiring precise indications and careful patient selection. Endoscopic ultrasonography (EUS) can verify the presence of bile duct stones prior to ERCP. The current ESGE recommendations permit ERCP in high-risk patients without confirmation; however, several individuals undergo ERCP without evident advantage, indicating a necessity for enhanced stratification. Objectives: We aim to evaluate the rate of EUS-validated choledocholithiasis in patients with suspected common bile duct (CBD) stones and to determine the predictors of residual stones. A secondary objective was to create and internally validate a streamlined scoring system to enhance risk assessment in ESGE high-risk patients. Methods: We conducted a retrospective analysis of patients who had endoscopic ultrasound for suspected choledocholithiasis from January 2023 to December 2024 at a tertiary center. Multivariate logistic regression determined independent predictors of retained calculi. A simplified score was derived from model coefficients and internally validated. Results: Among 438 examined patients, 186 were included and 87 had choledocholithiasis confirmed via EUS. ERCP was conducted in 81 patients and postponed for 6 patients due to contraindications. According to the ESGE criteria, 10 patients (5.4%) were classified as low risk, 92 (49.5%) as intermediate risk, and 84 (45.2%) as high risk for choledocholithiasis. For high-risk individuals, EUS identified stones in 45 (53.5%), while 39 (46.4%) experienced spontaneous clearance. Acute pancreatitis (aOR 0.075), cholangitis (aOR 6.939), and EUS CBD diameter (aOR 1.220 per mm) were independent predictors of stones. The resultant three-component score (−2 to +4 points) demonstrated effective discrimination (AUROC 0.788). A criterion of ≥2 resulted in 85.7% sensitivity and 59.0% specificity. Conclusions: Almost fifty percent of ESGE high-risk patients were not found to have CBD stones during EUS. Integrating EUS data with a straightforward predictive score may enhance risk classification and avert superfluous ERCP procedures.