| disease | Bile Duct Stones and Cholangitis |
Bile duct stones are divided into primary and secondary types. Primary bile duct stones originate within the bile duct system (including intrahepatic bile ducts) and are mostly pigment mixed stones containing a large amount of calcium bilirubinate. Gallstones must be present in the gallbladder. In China, most bile duct stones fall into this category. Secondary bile duct stones are formed when gallstones enter the common bile duct through an enlarged cystic duct. The shape and nature of these stones are usually similar to those of the gallstones, often presenting as multifaceted cholesterol mixed stones. Due to secondary biliary tract infection, the outer layer of these stones often has calcium bilirubinate deposits.
bubble_chart Epidemiology
The incidence of secondary bile duct stones in patients with gallbladder stones is 6-19.5%, and the incidence increases with age. In 1970, Harvard reported that 6.5% of patients under 40 years old who underwent cholecystectomy had secondary common bile duct stones, while the rate was 42% for those aged 70-80 and could reach 50% for those over 80.
bubble_chart Pathological Changes
The pathological changes caused by common bile duct stones mainly depend on the degree of obstruction caused by the stones and the presence of secondary infections. The obstruction of the bile duct by stones is generally incomplete and intermittent. The bile duct proximal to the obstruction may exhibit varying degrees of dilation and wall thickening. Since the obstruction is usually incomplete, it rarely affects the liver tissue significantly. However, bile stasis often occurs in the bile duct proximal to the obstruction, making it highly susceptible to secondary infections by Gram-negative bacilli. Stones located in the ampulla are more likely to cause complete obstruction of the bile duct. In such cases, if a bile duct infection occurs, the condition can rapidly worsen, leading to high pressure within the bile duct. Pus and bacterial toxins in the bile duct may reflux upward, breaking through the hepatic bile capillaries and entering the bloodstream, resulting in so-called obstructive suppurative cholangitis. Severe cases often lead to death due to toxic shock. Both obstruction and infection can cause damage to hepatocytes, leading to liver cell necrosis and fibrous tissue proliferation around the bile ducts, eventually resulting in biliary cirrhosis. When common bile duct stones affect the pancreatic duct, they may also lead to secondary acute pancreatitis, known as gallstone pancreatitis.
bubble_chart Clinical ManifestationsThe typical clinical manifestations of common bile duct stones are biliary colicky pain, fever, shivering, and jaundice, known as Charcot's triad. However, many patients lack the complete triad presentation. Most patients experience sudden colicky pain below the xiphoid process,偏向 the right, which may radiate to the right shoulder and back, but a few may have no pain at all, only feeling upper abdominal fullness and discomfort. About two-thirds of patients develop shivering and high fever following an episode of acute abdominal pain. Jaundice generally appears 12–24 hours after the onset of abdominal pain, by which time the abdominal pain has often subsided. The jaundice is usually not severe and tends to fluctuate. Occasionally, jaundice may be the sole clinical manifestation in a few patients with common bile duct stones. Jaundice is often accompanied by dark urine, pale stools, and cutaneous pruritus. Physical examination reveals tenderness and muscle guarding in the upper abdomen and right upper quadrant, and the gallbladder is usually not palpable. In patients with a prolonged course, an enlarged liver and spleen may be palpable, with the liver having a firm texture.
The diagnosis of common bile duct stones is generally not difficult in patients with typical Charcot's triad, especially those with a history of gallstones. However, for those presenting with only one or two symptoms of the triad, diagnosis often requires auxiliary examination methods. For patients without jaundice, intravenous cholangiography can reveal stones in the bile duct and dilated bile ducts. In jaundiced patients, it is necessary to differentiate between obstructive jaundice caused by tumors or intrahepatic gallstone stasis, and hepatocellular jaundice due to liver disease or hepatitis. When the bile duct is obstructed by a tumor (such as pancreatic head cancer or ampullary cancer), jaundice usually progresses and deepens, and a painless, enlarged gallbladder is often palpable on physical examination, accompanied by signs of cachexia. Jaundice caused by liver disease or hepatitis is generally mild, not associated with a history of abdominal colicky pain, and liver function tests often show significant abnormalities. Intrahepatic gallstone stasis also typically lacks a history of abdominal pain but may have a history of specific medication use. Ultrasound examination in these latter two conditions shows no dilation of the gallbladder or bile ducts. In contrast, bile duct obstruction caused by stones presents with typical fluctuating jaundice in addition to biliary colicky pain. If there is no infection, liver function is usually within the normal range. In diagnostically challenging cases, examinations such as PTC, CT, ERCP, and isotopic hepatobiliary imaging can aid in differential diagnosis.
The primary treatment is surgical intervention. Common bile duct exploration or choledocholithotomy is performed, with T-tube drainage of the common bile duct. Routine intraoperative cholangiography via the T-tube can reduce the occurrence of residual bile duct stones. After surgical exploration of the bile duct, choledochoscopy may also be used to confirm whether any stones remain in the bile duct. Choledochoscopy can locate and remove residual bile duct stones. Postoperatively, the T-tube is left in place for 10–14 days. Once the patient's jaundice has largely subsided, systemic and local bile duct infections are under control, and cholangiography confirms the absence of residual stones with unobstructed bile flow from the bile duct to the duodenum, the T-tube can be removed. Residual and recurrent stones in the bile duct have always been the most troublesome issues following surgical treatment of common bile duct stones, particularly in patients with primary bile duct stones, where the stones are often numerous, fragmented, and composed of calcium bilirubinate, making complete removal difficult and frequently leading to postoperative residuals. Even if the stones are largely removed during surgery in such patients, the recurrence rate remains high postoperatively. For this reason, many scholars suggest that for these patients, every effort should be made during the initial surgery to remove as many stones as possible using intraoperative cholangiography and choledochoscopy. If residual stones persist postoperatively and cannot be removed by non-{|###|}surgical therapy{|###|}, or if stones recur months or years later, a repeat choledocholithotomy should be accompanied by a biliary-enteric drainage procedure, such as choledochoduodenostomy, sphincteroplasty, or choledochojejunostomy. The main drawback of the first two drainage procedures is the high likelihood of postoperative reflux cholangitis due to food regurgitation. Reflux cholangitis is less common after choledochojejunostomy. Some also advocate performing biliary drainage during the first choledocholithotomy if muddy, pigmented stones are found. After biliary drainage, a patent drainage pathway is established between the bile duct and the intestine, allowing bile duct stones to pass into the intestine. This approach is quite valuable for reducing postoperative stone recurrence, expelling potential residual stones, and alleviating biliary symptoms. If the stone is impacted at the ampulla of Vater, sphincteroplasty is the procedure of choice.
