Cholelithiasis, Cholecystitis and Pancreatitis

Question 1

Contents of bile and its purpose?

Answer 1

Contents:

• Water
• Bile acids
• Bilirubin
• Cholesterol
• Excreted hormones and drugs

Function - digestion of fats and excretion of bilirubin, cholesterol and xenobiotics.

Question 2

How are types of cholelithiasis classified?

What are the types?

Answer 2

Classified based on constituents of the stone:

Cholesterol

• Cholesterol monohydrate
• Yellowy colour

Pigment stones

• Black - Unconjugated bilirubin + calcium = calcium bilirubinate
• Brown - Lipids, calcium salts of fatty acids, bilirubin, cholesterol

Question 3

Pathogenesis of cholesterol stone?

What conditions increase this risk? (4)

Answer 3

Bile cholesterol concentration becomes supersaturated, causing choletserol to form cholesterol monohydrate crystals.

Four conditions:

• Supersaturation of cholesterol
• Hypomotility of gall bladder
• Choletserol nucleation
• Hypersecretion of mucous that traps cholesterol crystals

Question 4

Pathogenesis of black pigment gall stone?

Answer 4

Disorders that lead to elevated levels of bilirubin.

Unconjugated bilirubin combines with calcium to form calcium bilirubinate.

Question 5

Consequences of a bile stone?

Answer 5

80% of patients remain asymptomatic.

Consequences:

• Biliary colic
• Increased risk of carcinoma
• Cholecystitis

Question 6

How is cholecystitis classed?

Answer 6

Acute or chronic, calculous or acalculous. (4 types)

Question 7

Presentation of acute cholecystitis?

Answer 7

• RUQ pain
• Fever
• Murphy’s sign

Question 8

Cause of acute calculous and acute acalculous cholecystitis?

Answer 8

Acute calculous - gallstone obstruction of neck or cystic duct

Acute acalculous - associated with pre-existing conditions e.g. trauma, sepsis, surgery.

Question 9

Mechanism of complications of acute cholecystititis?

Answer 9

Bile stasis and increased viscosity results in obstruction, mucosal ischaemia, pre-disposition to infection.

Question 10

Treatment of cholecystitis?

Answer 10

• Nil by mouth
• Pain relief
• Prompt surgery

Question 11

Prevalence of calculous vs acalculous chronic cholecystitis and its presentation?

Answer 11

90% calculous, 10% acalculous

Presents with RUQ pain, precipitated by food.

Question 12

Aetiology of acute pancreatitis

Answer 12

• Alcoholism
• Gall stone, tumour → obsturctiion
• Vasculitis
• Mumps

Question 13

Mechanism of acute pancreatitis complications?

Answer 13

1. Pancreatic duct obstruction
2. Acninar cell injury from alcohol

Leads to two bad consequences:

• Autodigestion of pancreas due to inappropriately released enzymes
• Fat necrosis - release of fatty acids bind calcium/magnesium to form insoluble soaps, causing fat necrosis.

Question 14

Macroscopic morphological differences between acute and chronic pancreatitis?

Answer 14

Acute pancreatitis:

• Swollen
• Haemorrhagic
• Fat necrosis

Chronic pancreatitis

• Shrunken
• Hard
• Pale due to fibrosis and calcification

Question 15

Pathogenesis of chronic pancreatitis?

Answer 15

Acinar compartments are replaced by fibrosis, leading to exocrine insufficiency and endocrine parenchymal destruction

Caused by long term alcohol misuse:

• Alcohol increases protein concentration in pancreatic fluid - plug up pancreatic ducts
• Alcohol damages acinar cells