This 65 year-old lady presented with a two week history of jaundice, pale stools and dark urine.
Abdominal examination was unremarkable. Her urine contained conjugated bilirubin. Her liver function
tests showed an obstructive picture. An abdominal ultrasound scan showed stones within the gall bladder
and a common bile duct (CBD) dilated to 18mm. The clinical picture was that of obstructive jaundice secondary to
gallstones. She proceeded to endoscopic retrograde cholangiopancreatography (ERCP). Two large stones
were identified within the bile duct. An endoscopic sphincterotomy was performed and an attempt to extract
the stones with a balloon catheter and Dormia basket failed. A biliary stent was inserted. A subsequent
attempt to crush the stones with a mechanical lithotripter also failed. She proceeded to an open
cholecystectomy and exploration of her CBD. The stones were extracted and a T-tube inserted. A
subsequent T-tube cholangiogram performed,10 days postoperatively, showed no retained stones and the tube was
removed without complication.
Common bile duct stones are seen in approximately 15% of patients with gallstones. Most bile duct
stones are believed to form in the gallbladder and to migrate to the bile duct. Some stones may form de
novo within the bile duct. These are often softer and more friable than gall bladder calculi.
Many small bile duct stones are asymptomatic and, if small, may pass spontaneously. If bile duct stones
are symptomatic, they present with either obstructive jaundice, acute pancreatitis or acute cholangitis.
When open cholecystectomy was widely practiced, an on-table cholangiogram was often performed to exclude CBD
stones. With the advent of laparoscopic cholecystectomy, the pre-operative prediction of common bile duct
stones has attracted much attention in order to perform ERCP selectively on patients at high risk of CBD stones
and to avoid further investigation in other patients. The presence of jaundice, a CBD diameter of greater
than 12 mm and an increased alkaline phosphatase is 90% predictive of the presence of bile duct stones. If
there is no history of jaundice and both the CBD diameter and alkaline phosphatase are normal then the
risk of a CBD stone is 0.2%.
ERCP is the 'gold standard' investigation for the detection of CBD stones. It has the advantage of also
being a potentially therapeutic procedure. It is, however, an invasive procedure with attendant
morbidity. Overall, approximately 5% of patients develop complications. The mortality assocaited
with procedure is approximately 1%. About 1% of patients develop pancreatitis and 5% of those who undergo
a sphincterotomy develop late papillary stenosis. With the risk associated with ERCP, interest has been
shown in the non-invasive detection of CBD stones. Intravenous infusion cholangiography has an inadequate
sensitivity for the detection of bile duct stones. Recently, Magnetic resonance cholangiopancreatography
has been shown to have a sensitivity and specificity similar to that of ERCP. It has the potential to
reduce the number of negative pre-operative ERCPs performed.
Demartines N, Eisner L, Schnabel K, Fried R, Zuber M, Harder F.
Evaluation of magnetic resonance cholangiography in the management of bile duct stones. Arch Surg
2000; 135: 148-152.