Gallbladder & Biliary Tree Pathophysiology Flashcards
1
Q
Characteristics of bile
A
- yellow liquid
- amphopathic properties
- contributes to excretion of cholesterol, copper, meds & lipid digestion @ small bowel
- contents:
- water
- bile acids
- cholesterol
- phospholipids
- lecithin
- electrolyes
2
Q
Normal anatomy of biliary tract
A
- Bile synthesized @ liver ==> cannaliculi ==> intrahepatic ducts ==> R & L hepatic ducts ==> common hepatic duct
- @ fasting: sphincter of Oddi closed & gallbladder/bile duct peristalsis imhibited ==> bile flows from liver to cystic ducto ==> gallbladder for storage
- @ fed: increased CCK + vagal tone ==> peristalsis ==> transport of bile to duodenum
3
Q
Causes of gallstones
A
- bile composition = too much cholesterol, too little water or both
- supersaturation of bile w/cholesterol ==> cholesterol crystals ==> choleliths
- pathogenic factors:
- gallblader/dile duct stasis
- hereditary mutations @ cholesterol structure
- inflammation @ gallblader
4
Q
Types of choleliths
A
- cholesterol
- mainly cholesterol + bile acids, phospholipis, lecithin
- white/yellow color + greasy/soft
- pigment stones
- mainly calcium bilirubinate salts + mucin nidus
- occur when increased bilirubin in bile
- e.g. hemolytic states (sickle cell)
- black and hard
5
Q
Risk factors for gallstones
A
- cholesterol
- mechanisms: cholesterol mutations, bile acid hypersecretion, gallblader stasis
- risk factors:
- obesity
- rapid weight gain/loss
- female
- >30yo
- Latin American/Native American
- estrogen/contraceptive use
- Pigment
- hemolytic state: e.g. sickle cell
- Asian
6
Q
Dx of gallstones
A
- Dx: ultrasound
- can detect gallstones or cholecystitis (>90%)
- also sensitive to determine any ductal dilation
- more difficulty detecting bile duct stones (50%)
- CT may be considered if cause of pain is unclear/other orgas need to be evaluated
7
Q
Tx of gallstones
A
- Endoscopic retrograde cholangiopancreatography (ERCP)
- can remove stones, place stents
- small risk of pancreatitis
8
Q
Characteristics of biliary colic
A
- stones travel downstream and partially obstruct gallblader neck, cystic duct, or common bile duct
- biliary colic =
- after meals (particularly fatty ones)
- dull or crampy pain @ epigastrium/RUQ
- occurs w/in hour of eating and last 3-5 hours and then resolve spontaneously
9
Q
Mechanism/cause of cholecystitis
A
- gallstone lodges @ cystic duct & becomes impacted
- bacterial superinfection of gallbladder lumen ==> acute (calculous) cholecystitis = severe inflammation and/or ischemia of gallbladder
10
Q
Presentation of acute cholecystitis
A
- severe pain @ RUQ; radiating to right flank or shoulder
- nauseau
- fever
- TTP (deep) of RUQ
- Murphy’s sign: deep palpation on exhalation ==> pt. stops exhaling suddenly
11
Q
Management of acute cholecystitis
A
–NPO (gallbladder rest)
–IV hydration
–IV antibiotics
–Surgical removal of the gallbladder (cholecystectomy) when stable
–Percutaneous drainage of gallbadder in patients too ill for surgery
12
Q
Mechanism & Management of acalculous cholecystitis
A
- Usually caused by ischemia of gallbladder
- Risk factors = sepsis, recent surgery, trauma/burns, hypotension
- Vasculitis
- Symptoms, disease otherwise similar to ACC
- Treatment: drainage of gallbladder or cholecystectomy
13
Q
Mechanism/cause of choledocholithiasis
A
- cause: stone obstructs the common bile duct
- majority stones migrate from gallbladder
- ~10% form de novo @ CND
14
Q
Presentation of choledocholithiasis
A
- Jaundice, dark urine, and abdominal pain
- May also cause acute pancreatitis
15
Q
Diagnosis of choledocholithiasis
A
- Liver chemistries/CBC
- elevated conjugated bilirubin
- elevated serum transaminases
- elevated alkaline phosphatase
- elevated cholesterol
- if pancreatitis ==>
- raised serum lipase/amylase
- elevated INR (decreased vit K absorption)
- –Ultrasound
- –MRCP or ERCP
