Hepatic Surgery

Question 1

Describe the anatomy of the liver.

Answer 1

Sits in cranial abdomen, 2/3rds to the RHS of midline
4 lobes - left, right, caudate, quadrate
Attached to diaphragm, right kidney, lesser curvature of stomach and proximal duodenum
Vena cava runs through and is firmly attached

Question 2

Describe the blood supply of the liver.

Answer 2

Hepatic artery (oxygen-rich)
Portal vein (nutrient-rich) from intestines/spleen
Mix and drain into hepatic veins, then into caudal vena cava

Question 3

List some of the functions of the liver.

Answer 3

Synthesis/clearance of albumin
Metabolism of carbohydrates/lipids/amino acids
Production/activation of clotting factors
Clearance of toxins e.g. ammonia, drugs etc.
Immunoregulation
GI function
Storage of vitamins/fats/glycogen/copper

Question 4

List some potential clinical signs of liver impairment.

Answer 4

Hypoglycaemia, lethargy, weight loss
Clotting problems, haemorrhage
Drug sensitivity, neuro signs, PUPD, anorexia, vomiting
Endotoxaemia, sepsis
Weight loss, diarrhoea

Question 5

Describe the anatomy of the biliary tract.

Answer 5

Bile acids synthesised in liver, excreted into hepatic ducts to drain bile out of liver
Multiple hepatic ducts converge to form common bile duct

Question 6

How does bile move during digestion?

Answer 6

Bile flows out of gall bladder via cystic duct to common bile duct and into duodenum

Question 7

How does bile move when not digesting?

Answer 7

Bile drains from liver and into gall bladder via cystic duct
Stored and concentrated in gallbladder

Question 8

What are the two main functions of bile acids?

Answer 8

Help with digestion and absorption of fat
Neutralise gastric acid and inhibit gastric acid secretion to prevent intestinal ulceration

Question 9

What diagnostic tests can we run for hepatic disease?

Answer 9

Bloods - haem/biochem, blood gas/electrolyte analysis, dynamic bile acid testing
Urinalysis
Abdominal radiography (plain/constrast), ultrasound, CT/MRI/scintigraphy

Question 10

What medical management can be provided for hepatic disease prior to surgery?

Answer 10

Prescription diet - low protein/fat
Oral antibiotics - compensate for reduced immunoregulation, prevent endotoxaemia
Oral lactulose - bind ammonia for excretion, prevent hepatic encephalopathy

Question 11

What pre-op care should we give patients with hepatic disease?

Answer 11

Assess clotting times - APTT/PT (consider pre-treatment with vitamin K or FFP)
IV peri-op antibiotics - culture liver/bile/gallbladder as necessary
IVFT - correct electrolyte imbalances/hypoglycaemia
Blood typing
General nursing care!

Question 12

What are the main hepatic/biliary surgeries performed?

Answer 12

Liver biopsy
Partial/complete hepatic lobectomy
Surgical correction of portosystemic shunt
Cholecystectomy
Cholecystoenterostomy

Question 13

When would you need to perform a liver lobectomy?

Answer 13

Removal of masses/abscesses
Liver lobe torsion

Question 14

Define cholecystectomy and cholecystoenterostomy.

Answer 14

Cholecystectomy = removal of gallbladder
Cholecystoenterostomy = rerouting gallbladder to duodenum

Question 15

When are cholecystectomy / cholecystoenterostomy indicated?

Answer 15

Biliary tract rupture and bile peritonitis
Extrahepatic biliary obstruction e.g. gallbladder mucocele, choleliths, pancreatitis, neoplasia

Question 16

What peri-op considerations should we have for patients undergoing hepatic surgery?

Answer 16

Hypotension - monitor BP
Hypothermia
Haemorrhage/coagulation abnormalities
IVFT throughout
Avoid pre-med/induction drugs that undergo hepatic metabolism
Peri-op antibiotics
Ventilation?

Question 17

What post-op care should we provide to patients who have undergone hepatic surgery?

Answer 17

Hospitalised for 24hrs+, possible intensive care
Analgesia
Monitoring - TPR, BP, signs of haemorrhage/leakage of bile
Haem/biochem
Antibiotics if indicated
Nutrition i.e. prescription diet
Monitor for sepsis/SIRS

Question 18

Define a portosystemic shunt.

Answer 18

Anomalous blood vessel that connects hepatic portal vein with systemic venous circulation (caudal vena cava)
Bypasses liver and diverts some of portal blood supply away from liver

Question 19

Describe the different types of portosystemic shunts.

Answer 19

Congenital (most common) - extrahepatic / intrahepatic
Acquired - secondary to other disease