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Flashcards in Gallstones & Biliary Colic Deck (75)
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What is cholelithiasis?

cholelithiasis refers to the formation of hard stones in the gallbladder (gallstones)


this typically takes years to occur 


How common is cholelithiasis?


Are all of these cases symptomatic?

it is very common and affects 10-15% of the general population in the developed world


the vast majority of these cases are asymptomatic and only a small proportion present with complications of gallstones


Are gallstones themselves problematic?

No, gallstones themselves are not problematic in the vast majority of cases 


But they can predispose to other problems with the biliary tree


What % of gallstones lead to further problems with the biliary tree?


What are the most common presentations?

Each year, 1 - 4% of gallstones will have an acute presentation of biliary disease


about 60% of these are biliary colic


and 40% are acute cholecystitis 


How are gallstones generally classified?

they are classified as either cholesterol stones or pigment stones


in reality, they are usually mixed 




In what parts of the world are pigment stones and cholesterol stones more common?

  • cholesterol stones are more common in the developed world
    • in Europe & the USA, 75% of gallstones are cholesterol stones


  • pigment stones are more common in the developing world


What do cholesterol stones typically look like?

they are usually solitary and large 


stones of about 70% or more of cholesterol are usually smaller and more numerous 


the rest of the stone is made up of calcium compounds and protein


What are the 3 risk factors for cholesterol stones?

  • female gender


  • advancing age


  • obesity 


What do mixed stones tend to look like?

there are usually multiple stones and they are irregularly shaped 


How can pigment stones be divided into 2 categories?


What is the difference in appearance / composition?

Brown stones:

  • these tend to be softer
  • they contain a mixture of pigment, cholesterol and calcium salts


Black stones:

  • these are much harder and made of pure pigment


Why do women tend to have a higher incidence of gallstones than men?

  • cholesterol secretion is a massive factor in gallstone formation - particularly the proportion of cholesterol secreted in relation to the concentration of bile salts 


  • women naturally secrete a higher proportion of cholesterol than men


How does incidence of gallstones change with age?

incidence increases with age


  • at age 30 - 5% women and 2% of men have / have had gallstones


  • at age 55 - 20% women and 10% of men have / have had gallstones


  • at age 70 - 30% women and 20% of men have / have had gallstones


What are the racial differences in who develops gallstones?

  • more common in Scandinavia


  • more common in Native North and South American populations


What are the 6 main risk factors for developing gallstones?

  • weight
    • obesity 
    • sudden weight loss


  • family history


  • oestrogen
    • female gender
    • oral contraceptive pill


  • diet (high fat, low fibre)


  • increasing age
    • stones take time to form


  • diabetes 


What are the 4 Fs that are used to describe the typical patient with gallstones?

  • fair
  • fat
  • female
  • forty


What 3 factors are needed for the formation of cholesterol stones?

  • high concentration of cholesterol in the gallbladder


  • gallbladder stasis


  • products that promote the crystallisation of cholesterol
    • some lipoproteins found in bile will do this 


When do cholesterol stones form?


What is there insufficient quantities of and what process can increase the formation of stones?

  • cholesterol stones form when the concentration of micelles is not great enough to hold all the cholesterol within micelles


  • formation of stones is increased during fasting
    • particularly extended fasting (e.g. in IV nutrition)


  • fasting increases the concentration of cholesterol in the gallbladder relative to other solutes 


What type of bile pool do patients with cholesterol stones often have?

they generally have a smaller bile pool that circulates more often


What is the first stage in the formation of cholesterol stones?

cholesterol crystals initially form in bile that is supersaturated with cholesterol


this results in the production of "sludge"


What factors inhibit the formation of sludge?

  • caffeine


  • NSAIDs


  • bile salts 


What factors exacerbate the formation of sludge?

  • mucin


  • rapid weight loss


  • pregnancy


  • increased serum cholesterol
    • large amounts of body fat
    • female gender
    • advancing age
    • diabetes / high dietary fat


  • reduced bile production or circulation
    • e.g. in malabsorption (like Crohn's) where so much bile is lost, it cannot be replaced quickly enough


What 2 drugs can exacerbate the formation of sludge?

  • oral contraceptive pill


  • clofibrate
    • a fibrate drug that lowers plasma cholesterol by increasing cholesterol secretion in the bile 


What 2 things can happen to sludge after it has formed?

  • it can be reabsorbed


  • it can go on to form cholesterol stones 


  • only in 15% of cases will it go on to form stones


How long does the process of cholesterol stone formation take?


When is a cholecystectomy usually performed?

  • it takes around 8 years for a stone to form from the beginning of the initial process


  • in symptomatic patients, a cholescystectomy is usually performed 12 years after the process of stone formation began


How is the process of pigment stone formation related to cholesterol stone formation?


Where do pigments in bile come from?

  • the process of pigment stone formation is completely independent of that of cholesterol stones


  • pigments in bile are from bilirubin breakdown


What are the 3 main causes that can lead to pigment stones?

  • an increase in bilirubin load, as a result of haemolytic anaemia


  • pigments become less water soluble once in the bile as a result of the action of glucuronidases 


  • cirrhosis - due to depletion of glucuronidase inhibitors at the site


What is thought to be the major cause of pigment stones, relating to the action of glucuronidases?


Where is this more common and what is associated with?

  • most cases of pigment stones result from the subclinical bacterial colonisation of the gallbladder


  • common in East Asia and associated with E. coli



What do the stones related to the action of glucuronidases look like?


What about the 2 other causes of pigment stones?

  • stones associated with bacterial colonisation tend to be softer and brown and combined with calcium carbonate



  • the other 2 types are smaller, blacker and harder and more commonly encountered in the West 


Which gender is more commonly affected by pigment stones?

pigment stones affect both sexes equally