ICL 6.2: Gallstones Flashcards
what populations are more often effected by gallstones?
gallstones are one of the most prevalent and costly digestive diseases in western countries
12% of US population have gallstones with 1000,000 new cases/year (Increases with age).
it’s double in women (20-40%) than in men (10-15% of men)
an estimated 700,000 cholecystectomies/year
medical expenses exceeded $6 billion in year
common in Pima Indians/ rare in Eskimo
what are the 3 types of gallstones?
- cholesterol stones
pure and mixed cholesterols stones = 75% of gallstones
- pigmented stones
black stones (20%) and brown stones (4.5%)
- calcium stones; super rare
what are cholesterol gallstones?
most common type of gallstones in US (∼75%)
PURE cholesterol vs. MIXED (contain at least 50% cholesterol by weight).
consist of: cholesterol monohydrate crystals & precipitates of amorphous calcium bilirubinate, with calcium carbonate or phosphate in one of the crystalline polymorphs.
most of gallstones are “SILENT” & 1/3 cause symptoms & complications.
complications of gallstones result in 3000 deaths/year
what type of gallstones do Crohn’s patients have?
the bile acid is formed in the hepatocytes and secreted into the biliary tree
then it collects in the gallbladder when someone isn’t eating – when they eat the bile will get pushed to the duodenum and then the ileum –> the ileum is where bile acids get reabsorbed!!
that’s why Crohn’s of the ileum has higher cholesterol stone formation
how are cholesterol gallstones formed?
- cholesterol gallstones develop when bile contains too much cholesterol and not enough bile salts
- incomplete and infrequent emptying of the gallbladder may case the bile to become over concentrated and contribute to gallstone formation
- increased levels of the hormone estrogen
hypercholesterolemia in the blood doesn’t have anything to do with gallstones!! it’s just high cholesterol in the bile!! it has nothing to do with serum levels of cholesterol
what is the pathophysiology of cholesterol gallstones?
at least five primary defects must be present simultaneously for cholesterol gallstone formation:
- genetic factors causing hyper secretion of cholesterol in the bile; when there’s more cholesterol than bile salts they’ll accumulate and you’ll get a stone
- hyper motility of gallbladder
- rapid phase transitions
- hepatic hyper secretion
- intestinal factors
what is the difference between pure and mixed cholesterol gallstones?
PURE
1. large and yellow/white color
- composed purely or mainly of cholesterol
MIXED
1. multiple and smaller
- composed of 50%+ of cholesterol
which enzyme deficiency is related to cholesterol stones in pregnancy?
cholesterol 7 alpha-hydroxylate
deficiency of this means deficiency in bile salts which will lead to saturated bile with cholesterol!
what are the risks for cholesterol gallstone formation?
- age ( 50’s and 60’s ).
- female.
- obesity: increase cholesterol synthesis & excretion.
- weight loss
- TPN or any prolonged fasting state means the gallbladder won’t contract and the bile will get thick and form stones
- pregnancy ( more in multiparous).
- drugs: (Estrogen, Progesterone, Fibrate Birth control pills, Octreotide)
- genetic predisposition (i.e. Native American )
- terminal ileum disease like in Crohn’s (reduces bile acid pool)
what are the risk factors for a black pigmented stone?
they’re do to hemolysis aka destruction of RBCs!!
- female
- not associated with obesity
- older age
- chronic hemolysis like in SC disease or hereditary spherocytosis
- liver cirrhosis
what are the risk factors for a brown pigmented stone?
more cholesterol than black pigment stones; somewhat amenable to
CBD stone type > 2 years post cholecystectomy
common in asia
risks:
1. stasis
- infection (e. coli)
what imaging can you do to diagnose gallstone?
- ultrasound (ALWAYS must order because it’s safe, cheap and easy to do)
- MRCP
- EUS
- HIDA scan
- ERCP
- IOC
- CT scan
- MRI
if you’re looking for a stone in the gallbladder, what imagining is best?
ultrasoun
what is ultrasound imagining used for?
- cholelithiasis > 95% accurate = stone in gallbladder
- choledocholethiasis = 50% accurate
- acute cholecystitis >90%
what is MRCP imaging used for?
choledocholethiasis
best stone to look for common bile duct stone; EUS if contraindicated
what is EUS imaging used for?
choledocholethiasis
stone in the bile duct but it’s minimally invasive so MRCP is better if you can do that
what is HIDA scan imaging used for?
acute cholecystitis = 95% accurate
this is the most specific test for cholysystitis, not the most sensitive; that’s US
what is ERCP imaging used for?
choledocholestiasis = 95% acurate
this is NOT a diagnostic test! ERCP is a therapeutic test, not diagnostic
what is CT/MRI imaging used for?
complications
can show stones in the gallbladder but it’s not good for looking at stones in bile duct
ex. if someone has pancreatitis from gallstones; not used just to look at stones
what is an intraoperative cholangiogram?
sometimes we dont know there’s a bile duct stone but we know there’s gallbladder stones
if there’s abnormal liver function tests this means there might be a stone in the bile duct – if the stones are just in the gallbladder even with cholocystits, liver function is normal because the drainage from the liver is still fine
so an IOC is used to look for bile duct stone
what is complicated gallstone disease?
- aute cholecystitis
- choledocholethiasis –> biliary colic, acute cholangitis, acute pancreatitis
- Mirizzi syndrome
- gallstone ileus
what is biliary colic?
intermittent blockage of biliary duct or cystic duct presenting with classic symptom of gallstone
intermittent obstruction of the cystic duct (NL LFTs)
severe epigastric or RUQ pain that:
1. lasts for < 6hrs
- may radiate to the shoulder blades
- may be post-prandial
- may associate with nausea or vomiting
classic history: intermittent attacks with pain-free periods between attacks
what is Mirizzi syndrome?
gallstone in the cystic duct and pressing on the bile duct without being completely in the bile duct
stone in cystic duct compressing or fistulaizing on the bile duct
obstruction of the common hepatic duct by an extrinsic compression from an impacted stone in the cystic duct or Hartmann’s pouch of the gallbladder.
symptoms can be jaundice, fever, right upper quadrant pain
how do you treat asymptomatic gallbladder stones?
risk of symptoms or complications is <1% per year
NO intervention (i.e. no surgery) Educate about potential development of symptoms
