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Introduction and epidemiology
Cholelithiasis refers to the presence of gallstones in the gallbladder, while choledocholithiasis refers to gallstones in the common bile duct. Gallstone disease refers to various clinical manifestations of the presence of gallstones, including:
- Uncomplicated gallstone disease
- Biliary colic
- Complicated gallstone disease
- Acute calculous cholecystitis
- Gallstone pancreatitis
- Gallstone ileus
Complicated gallstone disease refers to the presence of gallstone-related complications, like the ones mentioned above. Complicated gallstone disease may present with biliary colic. If biliary colic is present without gallstone-related complications, the condition is called uncomplicated gallstone disease.
The majority of gallstones are asymptomatic (and therefore not considered as gallbladder disease) and are discovered incidentally on imaging. Gallstones exist in 10 – 15% of the Western population, but only 1 – 4% become symptomatic.
Types and pathogenesis
Two types of stones exist. The most common type is the cholesterol stone, which accounts for 80% of all stones in the west. Bile formation is the only significant pathway for the body to eliminate excess cholesterol, either as free cholesterol or as bile salts. Cholesterol is dissolved in bile. The solution gets supersaturated if the cholesterol concentration exceeds the solubilization capacity of the bile.
Cholesterol won’t crystallize out of the solution until there is a nucleus, a “starting point” that it can precipitate onto. This nucleation process is then followed by growth, as more and more cholesterol precipitate into the nucleus, causing the stone to grow in size. Biliary stasis is also essential for the development of a stone.
It should be noted that most cholesterol stones aren’t comprised of only cholesterol. They most commonly also contain some bilirubin-calcium salts. Pure cholesterol stones are rare.
The second type of stone is the pigment stone, which is comprised of bilirubin-calcium salts. These usually occur in association with chronic haemolysis, which increases the production of bilirubin.
Cholesterol stones arise exclusively in the gallbladder and are yellowish. Pigment stones may arise anywhere in the biliary tree and are black or brownish.
The risk factors for the two different stones are different. For cholesterol stones:
- 6 Fs
- Fat (obesity)
- Fertile (multiparity or pregnancy)
- Forty (above 40 years of age)
- Fair-skinned (Caucasian)
- Family history
- Gallbladder stasis
For pigment stones:
- Chronic haemolytic anaemias
- Billiary infection
- Gastrointestinal disorders
- Crohn disease
- Ileal resection
- Cystic fibrosis with pancreatic insuficciency.
Uncomplicated (i.e., without cholecystitis, cholangitis, etc.) gallstone disease presents with biliary colic. This pain is intense, dull, constant, and is usually located in the right upper quadrant or epigastrium. The patient usually feels a strong urge to keep moving, rather than lying still. Worsening after food intake is typical but not always present. Sweating and nausea/vomiting is usually also present. Despite the name, the pain is usually constant rather than colicky. The attack usually lasts a few hours and rarely less than 30 minutes.
Cholecystitis usually presents with right upper quadrant pain which lasts longer than biliary colic, fever, nausea/vomiting, and positive Murphy sign (may be negative in elderly).
Cholangitis usually presents with Charcot’s triad of fever, abdominal pain, and jaundice.
Diagnosis and evaluation
Leukocytosis is often present in cholecystitis and cholangitis. An afebrile patient with biliary colic and normal WBCs likely has uncomplicated gallstone disease. Elevated liver enzymes, bilirubin, or jaundice is suspicious for choledocholithiasis, either cholangitis or pancreatitis.
Ultrasound is the most sensitive imaging modality for detecting gallbladder stones and is required for the diagnosis of gallstone disease. Ultrasound can also demonstrate gallbladder wall thickening or oedema, which gives the diagnosis of acute cholecystitis.
Abdominal CT may be used to rule out certain complicated gallstone diseases, like gangrenous cholecystitis, gallbladder perforation, emphysematous cholecystitis, or gallstone ileus.
For treatment, see the corresponding surgery topic.
- Gallstone ileus
- Acute gallstone pancreatitis
- Gallbladder gangrene or perforation
Gallstone ileus is a severe complication of gallstone disease where chronic inflammation of the gallbladder has formed a fistula between the gallbladder and duodenum, through which a gallstone can pass. This gallstone can obstruct the ileum, causing ileus. Gas inside the biliary tract on imaging is diagnostic.