Cholelithiasis

Cholelithiasis is the medical term for gallstones. In 1507, Antonio Benivieni, of Florence, Italy, reported an autopsy and marked the first correlation between clinical symptoms of gallstones with the diseased condition. 

Etiology

• Primary vs. Secondary gallstones
  • Primary: arise de novo in the gallbladder
  • Secondary: pass from gallbladder into bile duct
• Types of gallstones
  • Cholesterol stones (most common)
    • Precipitates from cholesterol-rich bile
    • NOT related to cholesterol levels in blood
    • Color: light yellow to dark green, chalk white
    • Risk factors: obesity, age, female, pregnancy, genetics, TPN, rapid weight loss
  • Pigmented (bilirubin) stones
    • Form from hemolysis → breakdown of RBCs
    • Color: dark black or blue
    • Risk factors: cirrhosis, ileal diseases, sickle cell anemia, cystic fibrosis
  • Mixed pigmented stones
    • Combination of calcium substrates, cholesterol, and bile
    • Color: brown
    • Risk factors: intraductal stasis, chronic colonization of bile with bacteria

Pathogenesis

• When bile isn’t completely drained from the gallbladder, it can precipitate as sludge, and then form into gallstones
• Major factors leading to gallstone formation
  • Supersaturation of secreted bile
  • Concentration of bile in the gallbladder
  • Crystal nucleation
  • Gallbladder dysmotility

History

• Symptomatic when obstructed, only 20 – 30% of patients with asymptomatic stones will develop symptoms within 20 years
• Biliary colic 
• RUQ pain following fatty meal

Physical exam → normal

Labs → normal

Imaging

• US
  • Best imaging for gallstones
  • 84% sensitivity, 99% specificity
  • Findings: [gallstone] hyperechoic structures within the gallbladder with distal acoustic shadowing, [sludge] hyperechoic layering within the gallbladder
• HIDA → if US is equivocal for ruling out acute cholecystitis
• CT abdomen
  • Can help determine if CBD dilatation is present
  • Detect pancreatic inflammation or complications
  • Useful if RUQ US excluded biliary disease
• MRCP
• ERCP

Treatment

• Asymptomatic cholelithiasis is a normal incidental finding and doesn’t usually require treatment unless they become symptomatic
• Prophylactic cholecystectomy
  • Considered in patients with higher risk of becoming symptomatic or with higher risk of gallbladder cancer
  • Sickle cell anemia
    • Hemolytic anemia
    • High rate of pigment stone formation
    • Cholecystitis can precipitate a sickle cell crisis
  • Calcified gallbladder [porcelain gallbladder]
  • Large (> 2.5 cm) gallstones
  • Long common channel of bile and pancreatic ducts
• Medical treatment is generally unsuccessful
  • Oral bite salt therapy
  • Contact dissolution
  • Lithotripsy 

Relevant Information

• Biliary colic occurs after a meal because CCK is secreted which leads to gallbladder contraction

Complications

• Cholecystitis
• Cholangitis
• Choledocholithiasis
• Gallstone pancreatitis
• Cholangiocarcinoma

Differential Diagnoses

• Acute pancreatitis
• Appendicitis
• Bile duct strictures
• Bile duct tumors
• Esophageal spasm
• Gallbladder cancer
• GERD
• Hepatitis
• Irritable bowel syndrome
• Pancreatic cancer
• Peptic ulcer disease