Medbear Gall Bladder Flashcards
Describe the anatomy of the gall bladder based on the following:
Anatomical areas
Location
Duct
- Gall bladder is divided into 4 anatomical areas: Fundus, Body, Infundibulum and Neck
- It is a pear-shaped sac
- Lies beneath segment 4 and 5
- Lined by SIMPLE COLUMNAR EPITHELIUM (It lacks muscularis mucosa and submucosa)
- Surface is covered by peritoneal serosa
It consists of
1. Common Hepatic Duct (~4cm) -> fusion of right and left hepatic duct
2. Cystic Duct (~4cm) - variation exists
3. Common Bile Duct (~10cm) -> no distinct muscle layer (So, no peristalsis)
State the boundaries for triangle of Calot
Lateral = Cystic duct
Medial = Common bile duct
Superior = Liver
Explain bilirubin metabolism
In complete biliary obstruction or severe intrahepatic cholestasis -> conjugated bilirubin leaks out and appears in urine -> Giving tea-colored urine and clay-colored stool (due to lack of formation of UROBILINOGEN)
State the composition of bile
- Water
- Phospholipids, electrolytes
- Bile salts - cholic acid, chenodeoxycholic acid
- Bile pigments - conjugated bilirubin
State the (4) functions of the gall bladder
- Reservoir for bile
- Concentration of bile -> active absorption of water, NaCl and HCO3 by mucus membrane of the gall bladder -> prevent gall bladder from being distended
- Secretion of mucus
- Gall bladder contraction stimulated by cholecystokinin (CCK), mediated by CHOLINERGIC VAGAL NEURONS
CCK half life = 2-3 minutes
Increase bile excretion - CKK, secretin, vagal input
Decrease bile excretion - somatostatin, sympathetic stimulation
Bile is normally neutral pH (But, increase in protein shifts bile to become acidic)
Define jaundice
- It is defined as yellow pigmentation of the skin and eyes due to excess bilirubin in the circulation
- Clinically detected if serum bilirubin levels >40 micromol/L
State Courvoisier’s law
In patients with a palpable enlarged gall bladder and painless jaundice, the cause is unlikely to be stone - malignancy until proven otherwise
What are the (5) exception that Courvoisier’s law doesn’t apply?
- Mirizzi’s syndrome - stones in the Hartmann’s pouch
- Double impaction - stones occluding cystic duct and distal CBD
- Oriental cholangiohepatitis - ductal stones form secondary to liver fluke infestation
- Congenital choledochal cyst
- Common hepatic duct obstruction
State the cause of obstructive jaundice based on the following:
Commonest cause
Painful obstructive jaundice
Painless obstructive jaundice
Commonest causes = gallstones, tumour, hepatitis
Painful obstructive jaundice = choledocolithiasis (+/- cholangitis), strictures, hepatic cause
Painless obstructive jaundice = PERIAMPULLARY TUMOUR
Give 3 differentials for post-operative jaundice
- Retained CBD stones
- Post-op biliary leak
- Injury to CBD +/- stricture formation
Define cholelithiasis
Refers to the presence of stone in the gall bladder
List the types of stones present in cholelithiasis with its corresponding incidence
- Cholesterol stone (85%)
- Pigment stone (15%)
- Black (sterile) gall stones -> Hard
- Brown (infected) gall stones -> Soft
- Mixed
- Biliary sludge
Describe on cholesterol gallstones based on the following
1. Radiolucent or radio-opaque
2. Risk factors
3. Pathophysiology
- Radiolucent
- Associated with 4F (Fat, Female, Forty, Fertile - estrogenic influence)
Pathophysiology:
- Increased cholesterol secretion in bile
- Decreased emptying of the gallbladder
Describe on black (sterile) gallstones based on the following:
1. Radiolucent or radio-opaque
2. Composed of
3. Pathophysiology
- Radio-opaque
- Composed of calcium salts (hard, speculated and brittle)
Pathophysiology:
- Increased secretion of bilirubin conjugates into bile
- Gallbladder hypomotility
- Decreased bilirubin solubilizes and bile stasis
Describe on brown (infected) gallstones based on the following:
1. Radiolucent or Radio-opaque
2. Composed of
3. Pathophysiology
- Radio-opaque -> formed in intra and extra-hepatic duct
- Composed of calcium salts and bacterial cell bodies
Pathophysiology:
- Infection - Enteric bacteria (E.coli, Klebsiella)
- Biliary stasis
What is biliary sludge?
- Microlithiasis suspended in bile
- Can be visualized on US scan
- Sludge is a pre-stone condition
20% of biliary sludge will disappear
Describe the biliary colic symptoms of cholelithiasis using SOCRATES
Site = Epigastric (70%) or RHC pain
Onset = usually occurs within hours of eating a meal
Character = waxing and waning character
Radiation = inferior angle of scapula or tip of right shoulder
Timing = distinct attack lasting 30 minutes to several hours
Associated symptoms =
- Patient gets better after vomiting
- Bloating, abdominal distension
- Back pain, LUQ pain
List the complicated conditions of cholelithiasis (In the gallbladder)
- Hydrops of gall bladder
- Acute calculous cholecystitis -> acute gangrenous cholecystitis / empyema of the gallbladder
- Porcelain gallbladder / chronic cholecystitis -> Increase risk of gall bladder cancer
- Gallbladder cancer
- Mirizzi’s syndrome
List the complicated conditions of cholelithiasis (In the common bile duct)
CHOLEDOCHOLITHIASIS leading to
- Obstructive jaundice
- Ascending cholangitis
- Secondary biliary cirrhosis
- Gallstone pancreatitis
List the complicated conditions of cholelithiasis (In the gut)
- Cholecystoenteric fistula formation -> Intestinal obstruction/gallstone ileus
- BOUVERET SYNDROME -> GOO (rare)
- Gallstone dyspepsia (non-ulcer dyspepsia) - fatty food intolerance, dyspepsia, flatulence
State the triad of gallstone ileus
- Gastric/small bowel dilatation
- Pneumobilia (Presence of gas in the biliary system)
- Intraluminal gallstone on CT
State what you would see on abdominal X-ray for gallstone ileus
Hint = RIGLER’S TRIAD
RIGLER’S TRIAD
- Distended small bowel loops
- Air in the biliary tree
- Radio-opaque stone in the right lower quadrant (rare)
Which is the most common site of obstruction for gallstone ileus?
Terminal ileum (2 feet proximal to ileocecal valve)
What imaging studies would you order for a case of cholelithiasis?
- Plain abdominal X-ray
- US scan (Investigation of choice) -> Shows strong echogenic rim around the stone + posterior acoustic shadowing
- MRCP
- ERCP -> If therapeutic indication is needed
ERCP
1. Stone removal (using FOGARTY-BALLOON CATHETER or DORMIA WIRE BASKET)
2. Sphincterotomy
-> to relieve obstruction or facilitate removal of stone
3. Stenting
