32 Biliary Flashcards
Cystic artery
Branch off right hepatic artery
Found in triangle of calot
Triangle of Calot
Cystic duct (lateral)
Common bile duct (medial)
Edge of liver (superior)
Blood supply to hepatic and common bile duct
Right hepatic (lateral)
Retroduodenal branches of the gastroduodenal artery (medial)
Longitudinal blood supply
Cystic veins drain:
Into right branch of the portal vein
Lymphatics in relation to common bile duct?
Right side
Parasympathetic nervous supply to biliary tree
Left (anterior) trunk of vagus
Sympathetic nervous supply to biliary tree
T7-10 (splanchnic and celiac ganglion)
How does the gallbladder normally fill?
Contraction of sphincter of Oddi
Characteristics of the gallbladder and biliary tree
No submucosa
Mucosa is columnar epithelium
Ducts do NOT have periastalsis
Effect on sphincter of Oddi: Morphine
Contraction
Effect on sphincter of Oddi: Glucagon
Relaxation
Normal sizes:
- Common bile duct
- Gallbladder wall
- Pancreatic duct
<8mm (<10 s/p chole)
<4mm
<4mm
Highest concentration of CCK and secretin cells are in:
The duodenum
Epithelial invaginations in the gallbladder wall
Rokitansky-Aschoff sinuses
FOrmed from increased gallbladder pressure
Biliary ducts that can leak after a cholecystectomy
Ducts of Luschka
Lie in the gallbladder fossa
What causes increased bile excretion?
CCK, secretin, vagal input
What causes decreased bile excretion?
Somatostatin, sympathetic stimulation
What causes gallbladder contraction?
CCK causes constant, steady, tonic contraction
Essential functions of bile?
Fat-soluble vitamin absorption
Essential fat absorption
Bilirubin and cholesterol excretion
How does the gallbladder form concentrated bile?
Active resoprtion of NaCl and water
Concentration of hepatic bile?
Concentration of gallbladder bile?
Na 140-170 (225-350)
Cl 50-120 (1-10)
BIle salts 1-50 (250-350)
Cholesterol 50-150 (300-700)
Active resorption of conjugated bile salts?
Terminal ileum (50%)
Passive resorption of nonconjugated bile salts?
Small intestine (45%) Colon (5%)
Postprandial gallbladder maximal emptying is at:
2hrs
Bile is secreted by:
Hepatocytes (80%)
Bile canalicular cells (20%)
Cholesterol and bile synthesis
HMG CoA > HMG CoA reductase > cholesterol > 7-a-hydroxylase > bile salts
Rate-limiting step in cholesterol synthesis?
HMG CoA reductase
Cholesterol stones
Nonpigmented stones
Causes: stasis, calcium nucleation, increased water reabsorption, decreased lecithin/bile salts
Found exclusively in the gallbladder
Black stones
Pigmented
Causes: hemolytic disorders, cirrhosis, ileal resection (loss of bile salts), chronic TPN
Due to increased bilirubin load, decreased hepatic function and bile stasis
Form in gallbladder
Brown stones
Pigmented
Cause: infection (deconjugates bilirubin)
Check for: ampullary stenosis, duodenal diverticula, abnormal sphincter of Oddi
Primary common bile duct stones
Tx: sphincteroplasty
Most common organisms in cholecystitis?
E. coli
Klebsiella
Enterococcus
Risk factors for gallstones
>40yo Female Obesity Pregnancy Rapid weight loss Vagotomy TPN (pigmented stones) Ileal resection (pigmented stones)
Best initial test for jaundice or RUQ pain?
Ultraound
Ultrasound findings - Hyperechoic focus, posterior shawdoing, movement of focus with changes in position
Cholelithysis
Ultrasound findings - Gallstones, gallbladder wall thickening, pericholecystic fluid
Acute cholecystitis
Ultrasound findings - dilated CBD
CBD stone and obstruction
HIDA scan
Technetium taken up by liver and excreted in the biliary tract
Findings on cholecystokinin cholecintigraphy that indicate need for cholecystectomy?
Gallbladder not seen (cystic duct likely has a stone)
Takes >60 minutes to empty (chronic cholecystitis)
Ejection fraction < 40% (biliary dyskinesia)
Most sensitive test for cholecystitis?
Cholecystokinin cholescintigraphy
Indications for immediate ERCP?
Signs that a common bile duct stone is present
Jaundice, cholangitis, US show stone in CBD
Indications for pre-op ERCP?
Persistently high for >24hrs:
- AST/ALT >200
- Bilirubin >4
- Amylase/lipase >1000