Extrahepatic bile duct stones can be classified as primary or secondary.
Etiology and Pathogenesis
Primary common bile duct stones are mostly brown pigment stones or mixed stones, typically occurring in patients with recurrent or persistent biliary tract infections. Risk factors for primary bile duct stones include periampullary diverticula, bile stasis, and a history of biliary ascariasis. Secondary extrahepatic bile duct stones refer to stones that originate in the gallbladder or intrahepatic bile ducts and migrate into the extrahepatic bile ducts. These account for approximately 85% of extrahepatic bile duct stones.
Clinical Manifestations
The presence of symptoms depends on whether the stones cause biliary obstruction and infection. Patients may remain asymptomatic if the stones do not obstruct the bile ducts. However, when stones obstruct the bile ducts and lead to secondary infections, the following complications may occur:
Acute Obstructive Suppurative Cholangitis
The classic presentation includes abdominal pain, chills with high fever, and jaundice, collectively known as Charcot’s triad.
Abdominal Pain
Pain is typically located in the epigastric region or right upper quadrant, often colicky in nature, with intermittent or persistent pain that worsens paroxysmally. Pain may radiate to the right shoulder or back and is often accompanied by nausea and emesis. Episodes are frequently triggered by the consumption of fatty foods.
Chills and High Fever
Obstruction of the bile duct increases intraductal pressure, often leading to secondary infections. Bacteria and toxins may reflux into the bloodstream through the hepatic sinusoids, resulting in sepsis, infectious shock, or disseminated intravascular coagulation (DIC). Fever is typically of the remittent type, with body temperature reaching 39–40°C.
Jaundice
Obstruction of the bile duct by stones may result in dark yellow urine and yellow discoloration of the skin and sclera. Some patients may also experience pruritus. Most patients have bile duct dilation above the site of obstruction, and stones may float upward, temporarily relieving the obstruction. Small stones may pass into the duodenum through the ampulla of Vater, leading to symptom resolution. Therefore, jaundice caused by extrahepatic bile duct stones may be intermittent and fluctuating. If the stone remains impacted and the inflammation worsens, patients may develop delirium, apathy, or coma, along with hypotension. When altered mental status and shock occur in addition to Charcot’s triad, the condition is referred to as Reynolds’ pentad, which is a highly dangerous situation with a high mortality rate, requiring urgent biliary decompression and drainage.
Acute and Chronic Cholangitis
Stones can cause biliary obstruction, bile stasis, and infection, leading to congestion and edema of the bile duct mucosa, which further exacerbates the obstruction. Recurrent episodes of cholangitis can result in fibrosis and thickening of the bile duct walls, narrowing of the ducts, and proximal bile duct dilation. Symptoms may include upper abdominal pain and jaundice.
Liver Damage and Biliary Pancreatitis
Bile duct stones and cholangitis can lead to hepatocyte necrosis and biliary liver abscesses. Recurrent infections and liver damage may progress to biliary cirrhosis. When stones become impacted at the ampulla of Vater, acute pancreatitis may occur.
Laboratory and Other Examinations
Laboratory Tests
Serum total bilirubin and conjugated bilirubin levels are elevated, along with increased serum transaminase and alkaline phosphatase levels. Urinary bilirubin levels are elevated, while urinary urobilinogen is reduced or absent, and fecal urobilinogen is decreased. In cases of concurrent cholangitis, leukocytosis with neutrophilia is often observed.
Imaging Studies
Abdominal ultrasound is a cost-effective diagnostic method and is considered a first-line approach. Magnetic resonance cholangiopancreatography (MRCP) is a non-invasive diagnostic tool with higher accuracy than abdominal ultrasound. It is considered the preferred method for identifying stones and determining their size and location. Endoscopic retrograde cholangiopancreatography (ERCP) has the highest diagnostic sensitivity for detecting extrahepatic bile duct stones and is regarded as the "gold standard" for diagnosis. ERCP can also facilitate therapeutic procedures such as endoscopic sphincterotomy (EST) and stone extraction, achieving both diagnostic and therapeutic goals simultaneously.
Diagnosis and Differential Diagnosis
The diagnosis can be established based on the presence of typical symptoms such as abdominal pain, chills with high fever, and jaundice, combined with laboratory findings of elevated serum total bilirubin and conjugated bilirubin, as well as imaging evidence of stones in the bile duct. Extrahepatic bile duct stones need to be differentiated from acute cholecystitis, acute pancreatitis, acute gastroenteritis, peptic ulcers, right renal colic, intestinal colic, and malignant tumors of the biliary system.
Treatment
General Management
Short-term fasting may be implemented, with intravenous administration of fluids, electrolytes, and nutritional support to maintain acid-base balance. Oxygen therapy and monitoring of vital signs are provided for critically ill patients.
Anti-Infection Therapy
Antibiotics are effective in treating 70%–80% of cases of acute cholangitis. Initial antibiotic therapy can be empirically selected in the absence of blood culture and drug sensitivity results. Third-generation cephalosporins combined with metronidazole, fluoroquinolones combined with metronidazole, or carbapenems alone are common options. If the infection is difficult to control, the choice of antibiotics can be guided by blood culture and sensitivity results.
Endoscopic Treatment
Endoscopic sphincterotomy (EST) with stone extraction and drainage is the preferred treatment for common bile duct stones with infection. Endoscopic treatment offers advantages such as minimal invasiveness, reduced pain, shorter hospital stays, and the ability to perform repeated stone extractions, making it especially suitable for elderly patients. For large stones, distal bile duct strictures, or patients at high surgical risk, biliary stent placement can be performed initially to relieve bile duct obstruction. Subsequent elective treatments such as endoscopic stone extraction, lithotripsy, or surgical intervention can then be planned.