Cholelithiasis (Gallstones)

Key Features

Essentials of Diagnosis

• Often asymptomatic

• Classic biliary pain ("episodic gallbladder pain") characterized by infrequent episodes of steady severe pain in epigastrium or right upper quadrant with radiation to right scapula

• Detected on ultrasonography

General Considerations

• Gallstones are classified according to their predominant composition

  • Cholesterol stones

  • Calcium bilirubinate stones

    • Comprise < 20% of the stones found in Europe or the United States

    • Comprise 30–40% of the stones found in Japan

Demographics

• More common in women than in men

• Incidence increases in both sexes and all races with aging

• In the United States, the prevalence of gallstones is 8.6% in women and 5.5% in men, with the highest rates in persons over age 60

• Although cholesterol gallstones are less common in black people, calcium bilirubinate cholelithiasis attributable to hemolysis occurs in over one-third of persons with sickle cell disease

• Native Americans of both the Northern and Southern Hemispheres have a high rate of cholesterol cholelithiasis, probably because of "thrifty" (LITH) genes that promote efficient calorie utilization and fat storage

• As many as 75% of Pima and other American Indian women over the age of 25 years have cholelithiasis

• Risk factors for gallstones

  • Obesity, especially in women

  • Rapid weight loss increases the risk of symptomatic gallstone formation

  • Diabetes mellitus and insulin resistance as well as a high intake of carbohydrates and hypertriglyceridemia

  • Pregnancy; also associated with increased risk of symptomatic gallbladder disease

  • Cirrhosis and hepatitis C virus infection (especially in men)

  • Certain drugs (clofibrate, octreotide, ceftriaxone)

  • Crohn disease

• Prolonged fasting (over 5–10 days) can lead to formation of biliary "sludge" (microlithiasis), which usually resolves with refeeding but can lead to gallstones or biliary symptoms

• Hormone replacement therapy conveys a slight risk for biliary tract surgery

Clinical Findings

Symptoms and Signs

• See Table 16–9

• Cholelithiasis is frequently asymptomatic and is discovered incidentally

• "Symptomatic" cholelithiasis usually means characteristic right upper quadrant or epigastric discomfort or pain (biliary pain)

• Small intestinal obstruction due to "gallstone ileus" is the initial manifestation in some patients

Differential Diagnosis

• Acute cholecystitis

• Acute pancreatitis

• Peptic ulcer disease

• Appendicitis

• Acute hepatitis

• Myocardial infarction

• Radicular pain in T6–T10 dermatome, eg, preeruptive zoster

Diagnosis

Laboratory Tests

• Table 16–9

• Laboratory tests are normal in persons with asymptomatic gallstones

Imaging Studies

• Ultrasonography is the most sensitive imaging modality

• CT is an alternative but usually not necessary

Diagnostic Procedures

• See Cholecystitis, Acute; or Choledocholithiasis & Cholangitis

Treatment

Medications

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