Description

• Stones in common bile duct (CBD)
• 3 types: Cholesterol (majority), calcium bilirubinate or pigment, and mixed stones
• Pigment stones may form de novo in the CBD.
• System(s) affected: Gastrointestinal; Hepatobiliary
• Synonym(s): CBD stones; CBD calculi

Epidemiology

• 700,000 cholecystectomies performed annually in the US:
  • 4.6–20% of patients with gallstones have choledocholithiasis discovered at time of cholecystectomy, depending on whether routine cholangiography is used.
• Increases with age (30–50% of patients >60 with gallstones have CBD stones):
  • On average, present 10 years older than cholelithiasis patients
• Incidence of gallstones in the US is 10–20%: Individuals >60 years old, up to 40%
• Internationally, incidence is increased due to parasitic infections (e.g., Ascaris lumbricoides).
• Choledocholithiasis found with intraoperative cholangiography may be a false positive, or may pass spontaneously without intervention.

Prevalence
Predominant sex: Female > Male

Risk Factors

• Cholelithiasis (most CBD stones migrate from the gallbladder [GB] into CBD)
• Pancreatitis (30%)
• Obesity
• Higher consumption of long-chain saturated fatty acids (1)[A]
• Chronic hemolysis
• Estrogen exposure
• Weight loss >25% of original weight (especially rapidly) after bariatric surgery (2)[A]
• Prior cholecystectomy:
  • <2 years prior: Considered a “retained” stone
  • >2 years prior: Considered “recurrent” stone

• MDR3 defects may predispose to bile sludge formation, cholelithiasis, cholestasis of pregnancy, and subsequent choledocholithiasis.
• Increased prevalence in Hispanic population

General Prevention

Maintain a healthy weight and lifestyle, and avoid rapid loss of excess weight.

Pathophysiology

CBD stones may be primary or secondary:

• Primary stones form within the biliary tract: Caused by any condition leading to bile stasis or chronic bactibilia
• Secondary stones form within the gallbladder

Etiology

• Cholelithiasis: Majority of stones
• Chronic hemolytic states
• Formation of de novo pigment stones:
  • Dilated, sclerosed, or strictured ducts (e.g., from recurrent cholangitis)
  • Hepatobiliary parasitism (A. lumbricoides or Clonorchis sinensis)

Commonly Associated Conditions

• Cholelithiasis, cholecystitis, cholangitis
• Gallstone pancreatitis
• Colorectal adenomas: Strong association between cholelithiasis and multiple (≥3) lesions (adjusted OR 2.39, 95% CI 1.21–4.72) and left-sided colorectal adenomas (adjusted OR 1.82, 95% CI 1.28–2.59) (3)[A]
• Cholangiocarcinoma (OR = 23.97, 95% CI 2.9–198.9) (4)[A]; cholecystectomy not preventative