Isolated CBD Dilation on Ultrasound Not Linked to Increased Choledocholithiasis Risk: Study
Researchers have found in a new study that pre-operative ultrasound showing isolated common bile duct (CBD) dilation does not increase the risk of choledocholithiasis (CD) compared to normal CBD diameter. Therefore, such findings should not influence the decision to perform an intraoperative cholangiogram during cholecystectomy. The study was published in the American Journal of Surgery by Benjamin R. and fellow researchers.
Asymptomatic choledocholithiasis symptomless stones in the common bile duct has been detected in about 5–15% of patients who undergo cholecystectomy for gallstones. Traditionally, a dilated CBD on pre-operative imaging, particularly ultrasound, has been a finding to indicate IOC during laparoscopic cholecystectomy to identify these occult stones. But the clinical significance of isolated CBD dilation dilation without other pathology has not been studied extensively. The purpose of this study was to evaluate if such isolated dilation does predict choledocholithiasis.
This was a retrospective observational study involving 341 patients who underwent laparoscopic cholecystectomy (LC) with intraoperative cholangiogram during the study period. Among these, 46 patients (13.5%) were identified as having isolated CBD dilation on pre-operative ultrasound.
CBD dilation was also termed as a diameter of ≥0.6 cm, with an additional 1 mm for each decade in patients aged more than 60 years to compensate for the changes due to aging. The researchers contrasted these 46 patients with the remaining cohort who presented with normal CBD diameter. Information gathered included demographic factors, laboratory investigations, severity of cholecystitis, complications, and readmission.
Key Findings
Solitary CBD dilation did not significantly predict a greater risk of choledocholithiasis on IOC.
The specificity of ultrasound-detected CBD dilation in the prediction of stones was 80.00%, but low at 25.49%.
The PPV was 17.39% only, reflecting that a majority of patients with dilation did not have bile duct stones.
NPV was 86.67%, i.e., patients without dilation were very unlikely to have choledocholithiasis.
There is no difference in patient demographics, cholecystitis severity, complications, or readmission from the hospital between the dilated and non-dilated patients.
This research concludes isolated pre-operative ultrasound common bile duct dilation is not a risk factor for choledocholithiasis and should not in itself dictate the intraoperative cholangiogram's use. These results support more individualized decision-making during intraoperative procedures and question the necessity of routine IOC based solely on CBD diameter.
Reference:
Ramser, B., Samuel, K., Pieracci, F. M., Morton, A., & Yeh, D. D. (2025). Isolated common bile duct dilation on pre-operative ultrasound is not a predictor of choledocholithiasis on intra-operative cholangiogram. American Journal of Surgery, 116478, 116478. https://doi.org/10.1016/j.amjsurg.2025.116478
