Background and study aims: Although abdominal ultrasonography (US) is a good initial screening method for detection of biliary tract disease, we sometimes encounter patients who only have findings of dilatation of the common bile duct (CBD) on US, without specific biliary symptoms or jaundice. This study aimed to evaluate the causes and clinical significance of dilatation of the CBD in patients without biliary symptoms, jaundice, or causative lesions at US.
Patients and methods: A total of 77 patients who had no biliary symptoms and whose internal CBD diameter was more than 7 mm, without definite causative lesions on US, were enrolled. Of these, 49 underwent endoscopic retrograde cholangiopancreatography (ERCP) and 28 underwent follow-up US or computed tomography (CT) instead of ERCP. We excluded patients whose bilirubin level had increased beyond the upper normal level or who had previous history of upper abdominal surgery including cholecystectomy.
Results: The ERCP findings were as follows: no lesion in 20 patients (40.8%), juxtapapillary duodenal diverticulum (JDD) in 11 (22.5%), benign stricture in ten (20.4%), distal CBD mass in two (4.1%), choledochal cyst in two (4.1%), anomalous union of the pancreaticobiliary duct (AUPBD) in two (4.1%), and choledochal cyst with AUPBD in two (4.1%). There were no differences in age or in alkaline phosphatase or gamma-glutamyl transpeptidase (GGT) levels between the patients who had causative lesions revealed at ERCP and those who did not. Among the 28 patients who did not undergo ERCP, 12 had returned to normal and eight had no change in CBD diameter on follow-up US. Among eight patients who underwent CT, there were four with normal findings, one with JDD, and three with suspected choledochal cysts.
Conclusions: We detected a significant number of causative biliary tract lesions in asymptomatic adults with dilatation of the CBD on routine abdominal US; no laboratory or demographic parameters were useful for discrimination. Further diagnostic study will be helpful for the early diagnosis of biliary tract disease in such patients.
Her biliary tree is dilated with both intrahepatic and extrahepatic
biliary dilatation. Her CBD measured 11 mm. This is a pathologically
dilated CBD. In over 95% of young normal subjects the common bile duct
measures less than 4mm. In the presence of gallstones the CBD can measure
up to 7mm without implying obstruction. The CBD can also dilate in the
elderly secondary to degeneration in the ductal wall and reach diameters
of up to 9mm. The CBD can also change in size physiologically in relation
to meals. In this patient there were gallstones readily visible in the
lower CBD on ultrasound. A diameter of the CBD of over 10mm is definitely
abnormal and will suggest the presence of stones in the CBD. In assessing
the CBD for stones, if ductal stones are seen then stones are present. If
CBD stones are not seen then this does not mean that they are absent since
there is a significant rate of false negative results, partly related to
the presence of obscuring gas in the duodenum.
Her initial presentation was during a consultation made by her
husband. Her symptoms seem relatively minor yet the biochemistry results
are quite abnormal indicating a pattern of obstructive jaundice. Her
ultrasound findings are dramatic with stones seen in the gallbladder and
in the lower common bile duct (CBD). Ultrasound is the first-line
investigation for the gallbladder and biliary tree. The ultrasound scan
should be available with only a short wait for more urgent cases. This
patient should be prioritised for an urgent scan appointment.
The relationship to ‘pathology’ seen on imaging to ‘disease’ and
clinical symptoms is interesting. Gallstones are common and an incidence
in excess of 10% in the population is described. It is common to find
gallstones in an otherwise asymptomatic patient. My policy is to tell
patients that they have gallstones even if they have no symptoms, however
I am always concerned that patients will then develop symptoms. I am
always surprised how patients can have significant radiological pathology
and have so few symptoms. The patient had obvious gallstones, a thickened
gallbladder wall, biliary dilatation and many CBD stones and yet had only
itching with a history of itching. The story of painless jaundice would be
more suggestive of pancreatic malignancy or a drug reaction rather than
The appearances of the liver are unexplained. Ultrasound is good for
assessing focal liver disease. A common abnormal pattern is the
geographical echogenic appearance seen in fatty change of the liver.
Similarly, Bruno et al studied 57 patients with normal liver enzymes (aminotransferases, gamma glutamyltranspeptidase and bilirubin) referred to EUS at our centre after prior negative imaging studies, excluding previous ERCP or history of biliary obstruction, pancreatitis or jaundice. Reasons for initial investigations were unspecific abdominal pain, dyspepsia, weight loss or pancreatic enzymes elevation in 49.2% of patients but in the majority of them biliary dilatation was an incidental finding. Employed imaging techniques, some of which performed in other centers, were TUS (7%), TUS and MRCP (63.1%), TUS and CT (10.5%) or TUS, MRCP and CT (19.3%). Abnormal EUS findings were observed in 12 patients (21%). As already described by other authors, causative identified lesions were periampullary diverticula, although a true compression on the CBD was rare (2/6), 2 ampullary adenoma, chronic pancreatitis according to predefined criteria in 2 cases, a 7-mm biliary stone and one pancreatic cancer; 66.7% of patients were completely asymptomatic while unspecific abdominal pain or dyspepsia had been reported by the others. As suggested by the authors, a 21% prevalence of pathologic findings among patients with the aforementioned features, is probably overestimated since chronic pancreatitis and periampullary diverticula without bile duct indentation are not sure causes of biliary dilatation. Excluding these cases, the percentage is lower (10.5%) and comparable with Malik’s findings.
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Core tip: Common bile duct dilatation, often without identified causes, in subjects with normal liver function tests and nonspecific abdominal symptoms, and absence of lesions on prior noninvasive imaging tests, is increasingly found in the clinical practice. Since the clinical suspicion for biliary pathology in that setting is usually low, and there are limited literature data, this condition is ignored. However, recent evidences show the existence of pathologies among these patients, often with a non-benign course. In this scenario, endoscopic ultrasound may have a role in the identification of the etiology of dilatation.
In recent years, the description of isolated bile duct dilatation has been increasingly observed in subjects with normal liver function tests and nonspecific abdominal symptoms, probably due to the widespread use of high-resolution imaging techniques. However, there is scant literature about the evolution of this condition and the impact of endoscopic ultrasound (EUS) in the diagnostic work up. When noninvasive imaging tests (transabdominal ultrasound, computed tomography or magnetic resonance cholangiopancreatography) fail to identify the cause of dilatation and clinical or biochemical alarm signs are absent, the probability of having biliary disease is considered low. In this setting, using EUS, the presence of pathologic findings (choledocholithiasis, strictures, chronic pancreatitis, ampullary or pancreatic tumors, cholangiocarcinoma), not always with a benign course, has been observed. The aim of this review has been to evaluate the prevalence of disease among non-jaundiced patients without signs of cytolysis and/or cholestasis and the assessment of EUS yield. Data point out to a promising role of EUS in the identification of a potential biliary pathology. EUS is a low invasive technique, with high accuracy, that could play a double cost-effective role: identifying pathologic conditions with dismal prognosis, in asymptomatic patients with negative prior imaging tests, and excluding pathologic conditions and further follow-up in healthy subjects.
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Several authors compared MRCP and EUS in detecting choledocholithiasis showing cost-effectiveness and higher accuracy of EUS in detecting distal small stones in non-dilated ducts[26,32,39]. De Lédinghen et al reported a 100% negative predictive value of EUS in the diagnosis of lithiasis, thus excluding the needing for further investigation and limiting unnecessary surgery. In the previously mentioned study by Scheiman et al, EUS was the most useful test for confirming a normal biliary tree, and the initial EUS strategy had the greatest cost-utility by avoiding unnecessary ERCPs and preventing ERCP-related complications.
Peer-review started: August 28, 2014
Correspondence to: Claudio De Angelis, MD, Professor, Department of Gastroenterology and Digestive Endoscopy, “Città della Salute e della Scienza”, University of Turin, corso Bramante 88, 10126 Turin, Italy. [email protected]