Pathophsyiology of gall bladder and biliary tree Flashcards
Main function of bile
bile acids are active ingredient
–lipid digestion
Bile synthesized by ___
secreted into ____
hepatocytes
cannaliculi, which drain into the peripheral intrahepatic bile ducts –> R, L hepatic ducts–> common bile duct
Gallbladder general function
Stores and concentrates bile (fasting)
Contracts to deliver bile to duodenum (fed)
Bile ducts
Conduit for bile
Excretion for cholesterol, minerals, certain drugs
Sphincter of Oddi
Conserves bile acids
Prevention of biliary infection (cholangitis)
During fasting state, vagal tone and CCK levels are low. Sphincter of Oddi remains closed. Bile flows into GB.
Gallstones
Genetic and acquired risk factors (lithogenic bile, nucleation (mucin plug), biliary stasis) Multiple causes in same patient Usually develop within the gallbladder -Biliary colic -Acute cholecystitis
May spill into bile duct
- Obstruction of CBD
- Pancreatitis
Most are asymptomatic
Types of gallstones
Cholesterol: most common soft, greasy, white-yellow always start in GB chol/bile salt supersaturation
Pigment:
black, hard, brittle
associated with bile stasis
calcium bilirubinate salts coalesce around mucin nidus
Brown:
least common
assoc w/ bacterial colonizaiton
Cholesterol lithogenesis
-cholesterol supersaturation
-phospholipid deficiency
-Occurs w/:
Gallbladder stasis
Chronic gallbladder inflammation
Cholesterol hyper-secretion by liver
Over-absorption of water in gallbladder
Mucin plug or foreign body nidus
Pigment stone lithogenesis
Chief constituent = calcium bilirubinate
Risk factors: Bile duct obstruction Excess bilirubin excretion (hemolysis) East Asian ancestry Parasitic infection
Gallstone RFs
Age > 30 Obesity Female gender Family history Pregnancy or estrogens Latin American or Native American ethnicity Rapid weight loss Biliary obstruction
“fat, female, forty, FH, from latin america”
Gallstone complications
Biliary colic Acute cholecystitis ascending cholangitis Gallstone pancreatitis Gallbladder carcinoma
Biliary colic
Intermittent pain in epigastrium or RUQ
After meals, particularly fatty foods
Builds over an hour, remits 3-8 hrs later
Occurs w movement of stone into cystic duct or gallbladder neck
Management of biliary colic
- may persist mo to yrs
- (Lap) cholecystectomy is curative
- Nonlithogenic bile acid supplement (ursodeoxycholic acid) may be considered
Acute calculous cholecystitis
Stone impaction in cystic duct or gallbladder neck
Bacteria colonization (GNRs, enterococci)
Transmural inflammation
Distension and ischemia
-GB perforation, sepsis or death may result if untreated
Presentation:
Severe RUQ pain, nausea, fever
Tx of acute calculous cholecystitis
NPO (gallbladder rest)
IV hydration
IV antibiotics
Surgical removal of the gallbladder (cholecystectomy)
Percutaneous or endoscopic drainage if too ill for surgery
Acalculous cholecystitis
Less common than calculous Usually from gallbladder ischemia Risk factors = sepsis, recent surgery, trauma/burns, hypotension Vasculitis Symptoms otherwise similar to ACC
Treatment:
Percutaneous drainage of gallbladder
Cholecystectomy if fit for surgery
Choledocholithiasis
Definition = stones in bile duct/s
Majority migrate from gallbladder
~ 10% form de novo in CBD
Presentation:
Jaundice, dark urine, and abdominal pain
Acute pancreatitis
Dx and management of choledocholithiasis
Diagnosis
Liver chemistries
Ultrasound
MRCP or ERCP
Management
ERCP with extraction and/or lithotripsy
Surgery for refractory cases
Ascending cholangitis
Bacterial infection of bile duct
Usually a complication of choledocholithiasis
Symptoms (Charcot’s triad)
Fever
RUQ pain
Jaundice
Sepsis or death may occur if untreated!
Reynold’s pentad: Charcot’s triad + hypotension + altered mental status
Dx and mgmt of Ascending cholangitis
Diagnosis:
History, labs, US
Initial management: Admit to hospital NPO Broad spectrum IV abx IV fluids
Definitive diagnosis/ management–> Urgent ERCP!!
Gallstone (biliary) pancreatitis
1 cause of acute pancreatitis in US
Clues : Risk factors for gallstones (“5Fs”) Gallstones seen on imaging Dilated bile duct Elevated liver chemistries Absence of other risk factors for pancreatitis
Biliary stricture
Narrowing (stenosis) of bile duct Intra- or extrahepatic Intrinsic or extrinsic Benign or malignant Symptoms more chronic and persistent than stones
Presentation of biliary stricture
Cholestasis: Jaundice Dark urine (choluria) Acholic stools Pruritus RUQ pain LFTs elevated in cholestatic pattern: Alk phos/GGT, bilirubin >> ALT/AST
Benign causes of biliary stricture
Iatrogenic - surgery, radiation Chronic pancreatitis Primary sclerosing cholangitis (PSC) Autoimmune pancreatitis Choledocolithiasis
