Gall bladder and biliary tract disorders

Question 1

Gall bladder : Function?

Answer 1

Gall bladder : stores bile produced in the liver
-Food with high fat content stimulate the gall bladder to secrete bile and bile emulsifies to fat to be absorbed

Question 2

Gall stones : Definition?

Answer 2

Stones formed in the gall bladder due to imbalance of chemical constituents of bile which precipitate out to form solid stones

Question 3

What are the contents in Bile?

Answer 3

Bile contents;
1. 70% - bile salts and acids, made up of cholesterol metabolisation
2. 10% cholesterol
3. 5% lipids
4. 5% proteins
5. 1% conjugated bilirubin

Question 4

Gall stones : Cholesterol stones (3)

Answer 4

1. Cholesterol stones - most common 80%
2. Composed primarily of cholesterol
3. Radiolucent - not visible on x-ray

Question 5

Gall stones : Bilirubin stones (3)

Answer 5

1. Composed primarily of unconjugated bilirubin, formed by hydrolysis of conjugated bilirubin
2. Cause - excess of bilirubin in the bile due to excess haemolytic
3. Radioluscent - visible on X-ray

Question 6

Gall stones : Brown pigmented gall stone

Answer 6

1. Infectious organisms can result in hydrolysis of conjugated bilirubin into unconjugated bilirubin, combine with calcium ions to form solid calcium bilirubinate stone
2. Gallbladder/biliary tract infection - stones can enter the common bile duct

Question 7

Gall stones : Risk factors

Answer 7

1. Oral contraceptives : (high oestrogen increases cholesterol and thus risk of gall stones)
2. Women > 40 years
3. Obesity and Diabetes
4. Pregnancy
5. Rapid weight loss

Question 8

Gall stones : Choledocholithiasis (definition + cause)

Answer 8

Definition :Gall stones in the common bile duct - obstruction of the outflow tract
Cause : stasis, infection
Labs : Affects liver infection, may cause liver damage - deranged LFTs

Question 9

Gall stones : Choledocholithiasis - Complications?

Answer 9

Cholangitis, acute pancreatitis

Question 10

Gall stones : Cholelithiasis (definition + cause + labs)

Answer 10

Definition : Gall stones in the gall bladder
Cause : imbalance of bile components,
Labs : Bile flow is not obstructed thus no liver dysfunction - normal LFTs
Tx - only if symptomatic

Question 11

Gall stone : Acute Cholecystitis - Definition and Pathophysiology

Answer 11

Definition : inflammation of the gall bladder usually caused by gall stone occlusion in the cystic duct

-Obstruct the flow of bile from the gall bladder into the small intestine - resulting in inflammation and pressure build up.

Question 12

Gall stone : Acute Cholecystitis - Clinical features

Answer 12

1. Epigastric pain radiating to the shoulder
2. N+V, jaundice, fever
3. Murphy’s sign +

Question 13

Gall stone : Acute Cholecystitis - Lab results

Answer 13

High level of conjugated bilirubin
Raised ALT - found in liver and biliary cells

Question 14

Gall stone : Acute Cholecystitis - Investigations for diagnosis

Answer 14

1. US
2. ERCP/MRCP

Question 15

Gall stone : Acute Cholecystitis - Management

Answer 15

1. Cholecystectomy

Question 16

Ascending Cholangitis : Definition

Answer 16

1. Acute infection of the bile duct caused by intestinal bacteria ascending from the duodenum

Question 17

Ascending Cholangitis : Pathophysiology

Answer 17

1. Gall stone form in the gallbladder and travel through the cystic duct into the common bile duct
2. Gall stone obstructs the common bile duct
3. Flow of bile from the liver is obstructed
4. Bacteria ascend from the duodenum into the bile duct
5. Infect the stagnant bile and surrounding tissues

Question 18

Ascending Cholangitis : Causative pathogens

Answer 18

Common pathogens : Ecoli, Klebsiella, enterobacter

Question 19

Ascending Cholangitis : Risk factors and complication?

Answer 19

1. Comp : Sepsis
2. RF : Gall stones

Question 20

Ascending Cholangitis : Clinical features

Answer 20

1. Charcot’s triad - RUQ pain, jaundice and fever
2. Reynold’s pentad - Charcot’s triad + hypotension/shock + altered consciousness

Question 21

Ascending Cholangitis : Investigations for diagnosis

Answer 21

US-ERCP : biliary dilation, duct wall thickening

Question 22

Ascending Cholangitis : Lab results

Answer 22

1. Raised WCC, raised CRP
2. Raised ALP, GGT, ALT

Question 23

Ascending Cholangitis : Management

Answer 23

1. IV antibiotics
2. ERCP within 24 hours- remove gall stones
3. Chlecystecomy

Question 24

Gall stone ileus : Definition

Answer 24

a gallstone passes from the gallbladder into the intestine and causes a blockage leading to bowel obstruction

Question 25

Gall stone ileus : Pathophysiology (6)

Answer 25

1. Chronic cholystitis may lead to repeated inflammation of the fall bladder - making the wall of the gallbladder oedematous and inflamed
2. This can cause it to adhere to nearby structures - most commonly the duodenum
3. Overtime, the gall bladder wall may thin out and cause a fistula to form between the gall bladder and the small intestine
4. Large gall stones can travel through this fistula and cause a blockage most commonly at the terminal ileum
5. Resulting in a mechanical bowel obstruction.
6. Obstruction leads to back up of fluid and air from the intestines

Question 26

Gall stone ileus : Clinical features (3)

Answer 26

1. Abdominal distention
2. N+V, hx of recurrent RUQ
3. Rigler’s triad - Pneumobilia (air in the bile ducts), evidence of small bowel obstruction and a gall stone outside the gall bladder

Question 27

Gall stone ileus : Investigations for diagnosis

Answer 27

1. US + AXR
2. CT scan

Question 28

Gall stone ileus : Management

Answer 28

1. IV fluids
2. NG tube to relive abdominal pressure from the UGI tract
3. Surgical intervention

Question 29

Bile Malabsorption : Defintion

Answer 29

Definition `; condition in which the digestive system fails to effectively absorb bile

Question 30

Bile Malabsorption : Pathophysiology

Answer 30

1. Bile is released into the small intestine to help emulsify fats,
2. Breaking them down into smaller particles that can be more easily absorbed.
3. The absorption of bile acids is particularly important for the digestion of dietary fats and fat-soluble vitamins (such as vitamins A, D, E, and K)
4. . When bile is not properly absorbed, it can lead to various digestive symptoms and nutritional deficiencies.

Question 31

Bile Malabsorption : Causes

Answer 31

1. Ileal Disease or Resection: e.g. Crohn’s disease

• The ileum, the final portion of the small intestine, is where bile acids are primarily absorbed.
• Diseases affecting the ileum, such as Crohn’s disease, or surgical removal of a portion of the ileum can lead to bile malabsorption.

2. Bile Acid Diarrhea: In some cases, there may be an excess of bile acids in the colon, leading to diarrhea.
   * This condition is sometimes referred to as bile acid diarrhea or bile acid malabsorption.
3. Biliary Obstruction: Conditions that obstruct the normal flow of bile from the liver to the small intestine, such as gallstones or tumors, can lead to impaired bile absorption.
4. Short Bowel Syndrome: Individuals with a shortened small intestine.

Question 32

Bile Malabsorption : Clinical features?

Answer 32

1. Chronic diarrhea, steatorrhea (fatty stools)
2. Abdominal discomfort
3. Deficiencies in fat-soluble vitamins

Question 33

Bile Malabsorption : Investigations for diagnosis

Answer 33

Bile Acid Sequestration Test:
* SeHCAT Test: This specialized nuclear medicine test involves the use of a radioactive substance (selenium homocholic acid taurine or SeHCAT) to assess the retention of bile acids in the body

Question 34

Bile Malabsorption : Management

Answer 34

Bile acid sequestrate e.g. Cholestyramine

Question 35

Cholestyramine : Mechanism of action and function

Answer 35

*Function : *Decrease in the levels of circulating bile acids and cholesterol in the bloodstream

MOA :
1. Binds to bile acids in the intestine.

2. Bile acids are produced by the liver and released into the small intestine to aid in the digestion and absorption of fats
3. Cholestyramine binds to these bile acids, forming a complex that is then excreted in the feces.
4. This process reduces the reabsorption of bile acids and increases the utilization of cholesterol in the liver to produce more bile acids.
5. The overall effect is a decrease in the levels of circulating bile acids and cholesterol in the bloodstream.

Question 36

Cholestyramine : Indication for use

Answer 36

1. Management of hyperlipidaemia - reduces LDL cholesterol
2. Following Cholecystectomy or Bowel resection to treat diarrhoea

Question 37

Cholestyramine : Side effects

Answer 37

1. Abdominal cramps and constipation
2. Decreases absorption of fat soluble molecules
3. Increases risk of cholesterol gall stones