Cholelithiasis / Cholecystitis

Question 1

Epidemiology of gallstones

Answer 1

Fair, fat (BMI>30), female, forty (age >40), fertile, low fibre diet (increased cholesterol reabsorption).

Question 2

What forms gallstones?

Answer 2

Formed from constituents of bile (cholesterol, bile pigments, phospholipids).

Question 3

What determines type of stone formed?

Answer 3

Relative concentrations determine stone formed (i.e. cholesterol will only crystallise into stones when bile is supersaturated with cholesterol relative to bile and phospholipid content).

Question 4

Features of cholesterol stones?

Answer 4

Large, often solitary.

Radiolucent stones.

Question 5

Features of pigment stones?

Answer 5

Small, radiolucent.
Less common.
May be ass/w haemolytic anaemia (increased pigment from Hb).

Question 6

What is biliary colic?

Answer 6

Transient obstruction of gallbladder (cystic duct neck) due to impacted stone. Resolves when stone falls back into GB/passes into CBD.

Question 7

What is the pain of biliary colic?

Answer 7

Severe gripping pain.

• often ass/w meals
• maximal in epigastrium and R hypochondriac region w/ radiation to the back
• continous over several hours (but may wax and wane in intensity); usually lasts at least 15min

Question 8

GB appearance in acute cholecystitis?

Answer 8

Thickened, inflammed, oedematous +/- gangrenous

Question 9

What is empyema of GB?

Answer 9

Unrelieved obstruction in presence of infected bile. Tender mass + rigours + marked pyrexia.

Question 10

Common organisms found in bile?

Answer 10

E. coli; Klebsiella aerogenes; Strep faecalis; Staphylococci; Clostridia; Salmonella.

Question 11

CF of acute cholecystitis?

Answer 11

• severe pain R hypochondrium; radiation to R subscap / shoulder
• tachycardia / pyrexia / vomiting / leukocytosis
• marked abdo tenderness of GB
• Murphy’s +ve

Question 12

What is Murphy’s sign?

Answer 12

Catching of breath at height of inspiration while GB is palpated.

Question 13

Ddx of acute cholecystitis?

Answer 13

• PUD
• High retrocaecal appendicitis
• Acute pancreatitis
• MI
• Basal pneumonia

Question 14

What is chronic cholecystitis?

Answer 14

Repeated bouts of biliary colic / acute cholecystitis –> fibrosis –> contraction of GB –> chronic inflammatory change with marked wall thickening.

Question 15

Hx of chronic cholecystitis?

Answer 15

Recurrent flatulence, fatty food intolerance and RUQ pain. Pain worse after meals and ass/w feeling of distension and heart burn.

Question 16

Ddx of chronic cholecystitis?

Answer 16

• PUD
• Hiatus hernia
• myocardial ischaemia
• Chronic pancreatitis
• GI neoplasia

Question 17

What is Couvoisier’s law?

Answer 17

Fibrosed GBs that contain stones cannot distend when pressure increases in the obstructed biliary tree. If GB palpable in presence of jaundice, jaundice unlikely to be due to stones.

Question 18

What is a mucocoele?

Answer 18

GB outlet obstruction in absence of infection. Imprisoned bile is absorbed, clear mucous continues to be secreted into distended GB.

Question 19

Presentation of mucocoele?

Answer 19

Hx of biliary colic + non-tender piriform swelling in R hypochondriac + lack of systemic upset + afebrile

Question 20

What is choledocholithiasis?

Answer 20

Gallstone in CBD

Question 21

Complications of choledocholithiasis?

Answer 21

Stones may pass spontantenously or give rise to:

• obstructive jaundice
• cholangitis
• acute pancreatitis

Question 22

When do gallstones cause acute pancreatitis?

Answer 22

When small stone obstructs ampulla of Vater.

Question 23

Is choledocholithiasis generally painful?

Answer 23

NO! Little muscle in CBD wall; unless impeded flow through Sphincter of Oddi.

Question 24

Pathophysiology of choledocholithiasis?

Answer 24

Impaction at sphincter impeded bile flow: jaundice, pale stools, dark urine.
Generally lasts several days.

Question 25

What is gallstone ileum?

Answer 25

Gallstoe perforates the gallbladder; ulcerates into duodenum; passes on to obstruct the terminal ileum.
Uncommon form of intestinal obstruction.

Question 26

What is cholangitis (inc CFx)?

Answer 26

Infection of the bile ducts causing RUQ pain, jaundice, fever + rigors.

Question 27

What is Charcot’s triad?

Answer 27

Fever, jaundice, RUQ pain.

Indicates cholangitis.

Question 28

Ix in suspected biliary colic / cholecystitis?

Answer 28

• LFT: may show cholestatic picture.
• Prothrombin time: prolongation may occur over a longer period due to Vit K (fat soluble) malabsorption
• Ultrasound examination may demonstrate stones in the gallbladder or bile ducts.
• ERCP: In the presence of duct dilation or stones, endoscopic retrograde cholangiopancreatography (ERCP) is usually performed. Dx and Rx —> allows spincterotomy and removal of stones.
• MRCP: Magentic resonance cholangiopancreatography and endoscopic ultrasound (EUS) help image biliary tree.
• Haemolysis screen: if pigment stones suspected or found operatively.

Question 29

Mx of gallstones?

Answer 29

• Cholecystectomy
• Medical dissolution (ursodeoxycholic acid up to 2years)
• Shockwave lithotripsy (limited efficacy)
• Sphincterectomy via ERCP
• If stones in biliary tree: (jaundice, cholangitis, pancreatitis) ==> IV ABs (prevent infection esp cholangitis).

Question 30

U/S features of gallstone?

Answer 30

• Echogenic
• Round
• Mobile
• Acoustic shadow

Question 31

Normal size of bile duct on U/S?