Liver pathology Flashcards
What are the functions of the liver?
- Storage
- Synthetic
- Metabolic
What is stored in the liver?
- Glycogen
- Vitamins
- Iron
- Copper
What is synthesised by the liver?
- Glucose
- Lipids/cholesterol
- Bile
- Clotting factors
- Albumin (main protein in systemic circulation)
What is the metabolic function of the liver?
- Detoxifying
- Bilirubin
- Ammonia
- Drugs
- Alcohol
What are the symptoms of liver pathology?
- Jaundice
- Oedema/ascites
- Bleeding
- Confusion
Why does liver pathology cause jaundice?
- Bilirubin not conjugated by the liver
Why does liver pathology cause oedema/ascites?
- Reduced ability of liver to synthesise albumin
- Leads to reduced oncotic pressure in the blood
- Water leaves circulation and cannot be drawn back from interstitium
Why does liver pathology lead to bleeding?
- Reduced clotting factor production
- Happens over a long period of time unless damage is extreme
Why does liver pathology lead to confusion?
- Impaired ammonia detoxification
- Ammonia is soluble + diffuses across blood brain barrier
What are the initial symptoms of liver pathology?
- Fatigue
- Nausea
- Abdominal pain
What can cause acute liver pathology?
- Alcohol
- Paracetamol
- Viruses (EBV, CBV)
- Medications e.g. aspirin in children
What is the difference between decompensated liver disease and acute liver failure?
- If jaundice, oedema/ascites, bleeding and confusion happen acutely = decompensated liver disease
- If this occurs without any history of liver disease = acute liver failure
What is cirrhosis?
- Permanent irreversible damage to liver resulting in impairment of function and distortion of liver architecture due to chronic inflammation
Outline how alcoholic liver disease causes a fatty liver
- Usually reversible
- Alcohol releases glucose as it’s broken down
- Insulin causes glucose to be stored as starch
- But if there’s an excessive amount it is stored as triglycerides
- Fatty deposits build up in the liver
- Large liver due to fat
Which drugs can cause liver inflammation?
- Iatrogenic drugs that become hepatotoxic
- Alcohol (alcoholic liver disease)
How does alcoholic liver disease progress?
- Fatty change (weeks) causes hepatomegaly
- Alcoholic hepatitis (years) causes right upper quadrant pain and jaundice
- Cirrhosis
Outline alcoholic hepatitis
- See inflammation and inflammatory cells in liver
- More severe symptoms
- Jaundice, RUQ pain, hepatomegaly, oedema, ascites
- Initially reversible but can become permanent if cirrhosis occurs
- Treat symptoms and reduce alcohol intake
Outline alcoholic hepatitis
- See inflammation and inflammatory cells in liver
- More severe symptoms
- Jaundice, RUQ pain, hepatomegaly, oedema, ascites
- Initially reversible but can become permanent if cirrhosis occurs
- Treat symptoms and reduce alcohol intake
Which infections can cause inflammation of the liver?
- Hepatitis B - vaccine, no cure, symptomatic
- Hepatitis C - IV drug use, cure, no vaccine, asymptomatic
- Hep C can lead to malignancy
What is NAFLD?
- Non-alcoholic fatty liver disease
- Insulin resistance
- Triglycerides accumulate in hepatocytes
- Cause inflammation
What is NASH?
- Non-alcoholic steatohepatitis
- inflammation
- more present due to obesity and diabetes
- Treat symptoms and reduce risk factors e.g. blood glucose levels
What is hereditary haemochromatosis and how does it affect the liver?
- Autosomal recessive
- Linked to increased ferritin levels
- Increased absorption of iron from small intestine
- Increased deposition in the liver
- Causes inflammation
- Treated with venesection
What is Wilson’s disease and how does it affect the liver?
- Decreased copper secretion from biliary system into circulation for removal
- Increased deposition of caeruloplasmin in blood
- Pt will ultimately need liver transplant
- Causes seizures, tremors and memory problems
What are the autoimmune causes of liver inflammation?
- Autoimmune hepatitis - hepatocytes are attacked by the autoantibodies ASMA and ANA
- Primary biliary cirrhosis due to autoantibody AMA
- Primary sclerosing cholangitis
What are the other causes for liver inflammation?
- Alpha antitrypsin
- Glycogen storage disease
- Budd-Chiari
What does the inferior mesenteric vein drain?
- Descending colon
- Drains into splenic vein
- Joins with SMV to make portal vein
What does the superior mesenteric vein drain?
- Ascending colon
What is portal hypertension?
- Main complication of cirrhosis
- Build-up of blood in portal venous system
Why does portal hypertension occur?
- Fibrotic tissue accumulates
- Liver less expansive
- Needs to be expansive because venous drainage from majority of GI tract passes through
Why does portal hypertension lead to ascites?
- Fibrosis compresses veins
- Increase in hydrostatic pressure in portal venous system
- Fluid leaks out
- Ascites
Why does portal hypertension lead to splenomegaly?
- Leads to increased pressure in splenic circulation
Why does portal hypertension cause varices?
- Increased pressure in portal circulation
- Blood shunts from portal circulation to systemic circulation
- Normally there are anastomoses between the 2 circulations, but these should not contain any blood
- Increased pressure in portal circulation causes distension of veins at these anastomoses
Outline oesophageal varices?
- Superior 2/3 drain into oesophageal veins and then to superior vena cava
- Distal 1/3 drains into left gastric vein and then to portal vein
- At junction there is crossover of veins where pressure can build
- Veins are superficial and fragile
- When they get dilated they are liable to rupture
- Causes significant haematemesis
- Can be life-threatening
Where can varices occur in the body?
- Oesophagus
- Anorectal
- Umbilicus
Outline ano-rectal varices
- Occurs between superior rectal vein and middle and inferior rectal veins
- Typically painless because they’re above the pectinate line
- Rarey bleed
Outline umbilical varices
- Less common
- Only occur if portal hypertension is severe
- Ligamentum teres (should be non-functional in adults) connects abdominal wall and circulation
- Caput medusa sign - pattern of superficial veins on abdominal wall
What is hepatorenal syndrome?
- Failing liver leads to failing kidneys
- Kidney deterioration is acute and rapid
Outline what happens to result in hepatorenal syndrome
- Portal hypertension backlogs through venous system
- Affects arterial circulation coming in (splanchnic)
- Vasodilation of splanchnic arteries to reduce pressure in system
- Perceived as decreased circulating volume because blood is stuck in portal system
- RAAS is activated
- Renal artery vasoconstriction occurs
- Decreased perfusion
- Reduced kidney function
Outline the flow of the bile ducts
- Bile ducts in liver coalesce
- Form left and right hepatic duct
- Left and right hepatic duct form common hepatic duct
- Cystic duct from gall bladder joins with common hepatic duct
- Forms common bile duct
What is the name of the site where the common bile duct and the pancreatic duct empty?
- Ampulla of Vater
- Sphincter of Oddi controls rate of release
What is biliary colic?
- Constant pain lasting for a few hours and then easing
- Gallstones cause sudden onset RUQ pain immediately after eating a large fatty meal
What causes biliary colic?
- CCK is released after eating a large fatty meal
- CCK release causes gallbladder to contract
- Gallstone is pushed up against neck of gallbladder
- Causes temporary obstruction to cystic duct and pain
- No inflammation
How is biliary colic treated?
- Give pain relief
- Plan operation to remove gallbladder
What is acute cholecystitis?
- RUQ pain
- Gallstone impacted in cystic duct so nothing can pass through
- Inflammation
- Positive Murphy’s sign
What is Murphy’s sign?
- Place hand on right side of liver
- Ask patient to take a deep breath in
- Gallbladder is pushed down and hits hand
- Causes intense pain
- Patient will inhale sharply
What is ascending cholangitis?
- Infection of biliary tree
What are the symptoms of ascending cholangitis?
Charcot’s triad:
1. RUQ pain
2. Inflammation
3. Jaundice
What causes ascending cholangitis?
- Happens when stone reaches common bile duct
- Causes stasis above point of blockage
- Causes infection behind stone
- Give antibiotics, fluids, surgical removal
What forms gallstones?
- Cholesterol
- Bile pigments
- Mixed
What are the risk factors for gallstones?
- Diet
- Female
- Forties
- Pregnancy
How are gallstones picked up on imaging?
- Ultra-sound scan
What leads to acute pancreatitis?
- Stone in common bile duct either at or after point at which pancreatic duct joins
- Causes complete obstruction of bile and enzymes of pancreas
- Auto-digestion
What are the symptoms of pancreatitis?
- Epigastric pain that goes to the back
- Vomiting
- Cullen’s and Grey-Turner’s
- Amylase and lipase increase in the blood
How do we diagnose pancreatitis?
- Look for raised amylase and lipase in the blood
- CT/MRI to look for inflammation
- Give lots of fluids for organ support
