Utility of common bile duct measurement in the diagnosis of cholecystitis and choledocholithiasis in children.

BACKGROUND

Ultrasound is an integral part of evaluating for acute cholecystitis and choledocholithiasis in pediatric patients. Finding the common bile duct (CBD), a structure which is normally <4 mm in children, can be very challenging.

OBJECTIVE

The primary objective of this study was to determine the prevalence of isolated sonographic CBD dilation in pediatric patients with acute cholecystitis and/or choledocholithiasis without laboratory abnormalities or pathologic findings on radiology based biliary ultrasound, apart from cholelithiasis.

METHODS

We conducted a retrospective chart review of patients ≤21-years-old, at a single free-standing tertiary care children's hospital, who received a biliary ultrasound in the radiology department (RADUS) from September 2005 to February 2020. We identified patients who had a diagnosis of acute cholecystitis and/or choledocholithiasis on RADUS. Based on prior studies, a positive ultrasound was defined as having gallbladder wall thickening (GWT), pericholecystic fluid (PCF), or sonographic Murphy's sign (SMS). The final diagnosis was confirmed using the gold standard, cholecystectomy pathology diagnosis for patients with cholecystitis and endoscopic retrograde cholangiopancreatography (ERCP) diagnosis for patients with choledocholithiasis. Ultrasound data and contemporaneous laboratory values were collected.

RESULTS

180 patients met inclusion criteria. For the study population, 97 (53.9%) had a positive ultrasound, 127 patients (70.6%) had a dilated CBD, and 170 (94.4%) had at least one abnormal laboratory finding. Within the study population there were 76 patients (42.3%) with acute cholecystitis, 55 patients (30.5%) with choledocholithiasis, and 49 patients (27.2%) with acute cholecystitis and choledocholithiasis. Of the 127 patients with a dilated CBD, 80 (62.9%) had a normal ultrasound, apart from cholelithiasis. In this group of 80, 78 patients (97.5%) had at least one abnormal laboratory finding. Thus, for the entire study population, isolated CBD dilation without a positive ultrasound or laboratory abnormalities occurred in 2 patients (1.1%). Of note, these 2 patients had an ultrasound diagnosis of choledocholithiasis.

CONCLUSION

The prevalence of isolated sonographic CBD dilation in pediatric patients with cholecystitis and/or choledocholithiasis was 1.1%. Thus, biliary ultrasound without CBD measurement is unlikely to result in missed cholecystitis and/or choledocholithiasis if the biliary ultrasound does not demonstrate GWT, PCF, SMS, or choledocholithiasis, and the patient has normal laboratory values.