What is a bile duct stone?
Bile duct stones (choledocholithiasis) are gallstones that are present in the bile ducts, sometimes within the cystic duct of the gallbladder but more frequently in the common bile duct. Most gallstones are formed in the gallbladder and if small enough, it will pass out into the cystic duct and then into the common bile duct (CBD) along with the flow of bile. These stones may lodge in the duct and become impacted thereby causing a blockage of the duct. Most small stones, however, will pass out with the bile into the duodenum of the small intestine. Less frequently, a stone may originate within the hepatic or common bile duct and this is referred to as a primary bile duct stone.
Causes of Bile Duct Stones
Cholesterol and black pigment stones more often originate in the gallbladder and may pass out into the bile duct. Brown pigment stones tend to develop within the bile ducts (primary bile duct stone) – hepatic or common bile duct. It is usually due to an infection (bacterial or parasitic) or bile stasis.
Symptoms of Bile Duct Stones
The majority of the cases of bile duct stones will pass out of the common bile duct unnoticed. However, if the stone is impacted in the bile duct, it will cause attacks of gallstone pain known as biliary colic. The obstruction caused by the stone will affect bile production and secretion and leads to obstructive jaundice. It can also further complicate into gallstone pancreatitis.
The signs and symptoms of bile duct stones are further discussed under the Symptoms of Gallstones.
Surgery for Bile Duct Stones
Bile duct stones are removed surgically by a procedure known as an endoscopic retrograde sphincterotomy (ERCP with sphincterotomy, ERS). This is a minimally invasive procedure with a quick recovery time. An open common bile duct exploration known as a choledocholithotomy may be considered if other surgical options are not available, the bile duct anatomy is complex or if the stone is large. The bile duct is not removed, unlike the gallbladder in a case of gallbladder stones, because bile from the liver and gallbladder need to enter the duodenum via this duct.
Surgical options for bile duct stones are discussed further under Gallstone Removal Surgery.
Treatment of Bile Duct Stones
The use of medication to dissolve a bile duct stone is not a feasible option since these drugs take months to be effective and are more useful for cholesterol stones. Prolonged obstruction of the bile duct, even a partial blockage, can cause severe discomfort and pain and lead to a host of complications that could even be life-threatening. Lithotripsy, which is the use of shock waves to fragment the stones is also not routinely done for bile duct stones.
Gallstone drugs and lithotripsy are discussed further under Gallstones Treatment.
Diet for Bile Duct Stones
Dietary changes may be ineffective for primary bile duct stones, especially pigment stones. However, a gallstone diet should be considered in a recurrent case of cholesterol gallstones.
These dietary changes are discussed further under Foods to Avoid for Gallstones.