Epidemiology
- Common in Fat, Fertile, Forty, Flatulent, Female
- Part of Saint’s triad – gallstones, diverticulosis, hiatus hernia
Etiology
Lifestyle
- Obesity, sedentary lifestyle
- Diet high in cholesterol
Infections/infestations
- Bacteria – E. coli, salmonella
- Parasites – Ascaris lumbricoides
Bile stasis
- Due to oestrogen therapy, pregnancy, vagotomy
Increased bilirubin production
- Any causes of hemolysis – hereditary spherocytosis, sickle cell anaemia, thalassemia, malaria, cirrhosis
Types
- Cholesterol stones – often solitary
- Mixed stones – most common
- Pigment stones – contain bilirubin, can be sludge like
Pathogenesis
Cholesterol stones
- Supersaturation – bile comes supersaturated with cholesterol
- Normal ratio of bile salts and lecithin to cholesterol is 25:1
- Ratio <13:1 leads to precipitation of cholesterol
- Hypomotility/stasis of the bile
- Nucleation – a glycoprotein in the bile causes formation of cholesterol monohydrate crystals
- Accretion – hypersecretion of mucous in the gallbladder traps the crystals and causes them to aggregate into stones
Mixed stones
- Composed of 20-50% cholesterol and other substances (calcium salts of carbonate, phosphate and palmitate; proteins)
- Often precipitated by infections
Pigment stones
- Formed due to excess bilirubin in the bile, which combines with calcium to form a solid precipitate
- Hemolytic anemias are the most common cause
Clinical Features
- Can be asymptomatic
- Colicky abdominal pain – in right upper quadrant, radiates to the back and shoulder
- Accompanied by nausea and vomiting
- Exacerbated in the supine position e.g. when sleeping
- Flatulent dyspepsia – abdominal discomfort, belching, heartburn
- Intolerance of fatty foods
Investigations
- US abdomen
- X-ray abdomen
- Liver function tests
- WBC count
Treatment
- Laparoscopic cholecystectomy
- Calot’s triangle is an important anatomic landmark during laparoscopic cholecystectomy
- Significance – allows surgeon to correctly identify and safely ligate the cystic duct and cystic artery
- Borders – inferior surface of liver, common hepatic duct, cystic duct
- Contents – right hepatic artery, cystic artery, lymph node of Lund
- Calot’s triangle is an important anatomic landmark during laparoscopic cholecystectomy
- Open cholecystectomy – in suspected common bile duct stones; Mirizzi syndrome; suspected gallbladder carcinoma
- Dissolution using ursodeoxycholic acid – for asymptomatic cholesterol stones
Complications
In the gallbladder
- Acute or chronic cholecystitis
- Empyema gallbladder
- Perforation – leading to biliary peritonitis
- Carcinoma gallbladder
In the common bile duct
- Secondary CBD stones
- Cholangitis
- Pancreatitis
- Mirizzi syndrome (see below)
In the intestine
- Cholecystoduodenal fistula – leads to gallstone ileus (intestinal obstruction
Mirizzi syndrome
- Extrinsic compression of an extrahepatic biliary duct from one or more calculi within the cystic duct or gallbladder
- Patients can present with recurrent episodes of jaundice and cholangitis
- Type I – extrinsic compression of the common hepatic duct (CHD)
- Type II – erosion of CHD wall and formation of cholecystocholedochal fistula (up to one-third CHD wall circumference is involved)
- Type III – up to two-thirds of CHD wall circumference is involved in a cholecystocholedochal fistula
- Type IV – entire CHD wall is involved in a cholecystocholedochal fistula