Obstructive jaundice

Question 1

What are the borders of Calot’s triangle and what is found within the triangle?

Answer 1

1. Inferior border of the liver
2. Cystic duct
3. CBD

Contains cystic artery, Lund’s lymph node (can be enlarged in cholangitis or cholecystitis)

Question 2

What effect does cholecystokinin have on the gallbladder and sphincter of oddi?

Answer 2

• gallbladder contract
• sphincter of oddi relaxes
• therefore bile exits the gallbladder and flows into the duodenum

Question 3

Explain the metabolism of bilirubin.

Answer 3

• unconjugated bilirubin is formed mainly in the spleen via breakdown of Hb
• it is insoluble and transported in the plasma bound to albumin
• taken up by the liver via active transport
• converted in the hepatocytes into conjugated bilirubin (water soluble)
• excreted into the bile canaliculi and via main bile ducts into duodenum
• 10% of the conjugated bilirubin is reduced to urobilinogen and excreted
• 90% of converted by colonic bacteria into stercobilinogen which is excreted in the faeces

Question 4

What are the S+S of obstructive jaundice?

Answer 4

• yellowing of the skin (jaundice)
• pale bulky stools
• dark urine
• pruritis
• abdo distension (acute hepatitis)
• abdo pain (gallstones)
• painless palpable gallbladder (carcinoma of the head of pancreas)

Question 5

What are the different types of jaundice?

Answer 5

1. Pre-hepatic: occurs when he rate of production of bilirubin is sufficiently fast to saturate the uptake-conjugation mechanisms of the liver
2. Hepatic: caused by some disorder of the hepatocytes at the stages of uptake, conjugation or secretion of bilirubin
3. Post-hepatic: occurs when there is obstruction to the CBS

Question 6

What can cause pre-hepatic jaundice?

Answer 6

• Haemolysis
• Haemolytic anaemias (spherocytosis, pernicious anaemia)
• Thalassaemia
• Trauma
• Gilbert’s syndrome most common inherited cause of unconjugated hyperbilirubinaemia).
• Crigler-Najjar syndrome (rare autosomal recessive disorder of bilirubin metabolism, caused by deficient diphosphate glycosyltransferase)

Question 7

What can cause hepatic jaundice?

Answer 7

• Congenital defect of hepatocyte function
• Hepatocellular injury or infection
• Viral hepatitis (including type A and type B). Other possible infective causes include leptospirosis, brucellosis, Coxiella burnetii) and glandular fever.
• Alcoholic hepatitis.
• Autoimmune hepatitis
• Drug-induced hepatitis: (paracetamol = most common cause of drug-induced liver disease)
  Hepatotoxic chemicals (phosphorous, carbon tetrachloride and phenol)
• Decompensated cirrhosis.

Question 8

What can cause post-hepatic jaundice?

Answer 8

Can be intrahepatic (metabolic) or extra hepatic (mechanical)

1. Intrahepatic:
   - Primary Biliary Cirrhosis (PBC)
   - Primary sclerosing cholangitis
   - Drugs (for example, phenothiazines)
   - Dubin-Johnson syndrome: autosomal recessive disorder characterised by conjugated hyperbilirubinaemia and deposition of pigment in hepatocytes
   - Rotor’s syndrome
2. Extrahepatic:
   - Bile duct strictures (can be benign or malignant)
   - Common duct stone
   - Cancer of the head of the pancreas
   - Tumour of the ampulla of Vater
   - Pancreatitis
   - Cancer of the gallbladder

Question 9

What is Courvoisier’s sign and what does it indicate?

Answer 9

• painless jaundice and palpable gallbladder

- indicates malignancy of the pancreas

Question 10

What blood tests should be carried out to determine the cause of jaundice?

Answer 10

1. Haemolytic causes:
   - increased unconjugated bilirubin
   - normal alkaline phosphatase
   - normal gamma glutamyl transferase
   - normal transaminases
   - normal lactate dehydrogenase
2. Hepatocellular causes:
   - increased unconjugated bilirubin
   - normal alk phos
   - increased GGT
   - increased transaminases
   - increased LDH
3. Obstructive causes:
   - normal unconjugated bilirubin
   - much increased all phos
   - much increased GGT
   - normal transaminases
   - normal LDH

• Reticulocytosis (haemolysis)
• Raised prothrombin time (parenchymal liver disease or cholestasis)
• Hepatitis screen (hepatocellular)
• Serum antibodies (PBC)

Question 11

What is the role of ERCP in diagnosing and managing obstructive jaundice?

Answer 11

• accurate at diagnosing benign and extra hepatic obstruction and can be combined with procedures to relieve obstruction
• if bile ducts are dilated and LFTs are not improving then it is an indication of ERCP
• if the patient has dilated ducts, it is likely to be gallstones, a bile duct stricture, or pancreatic cancer
• sphincterectomy: used for CBD stone extraction, treatment of ampullae strictures due to tumours or inflammation
• stent insert (plastic or expanding metal): used for bile duct stones that cannot be removed easily, post-op or benign strictures, malignant strictures, external compression of bile duct

Question 12

What is the role of surgery in treating obstructive jaundice?

Answer 12

• Surgical resection (Whipple’s pancreaticoduodenectomy): used from selected cases where pancreatic or distal bile duct tumours are benign or malignant
• Surgical drainage (choledochoduodenostomy or cholecystojejunostomy): very rarely used if other interventions have failed due to very high mobility and mortality