Liver - arteries, veins, nerve, lymph & Percutaneous Liver Biopsy

Question 1

what type of blood supply does the liver have?

Answer 1

unique dual blood supply

Question 2

what is the function of the hepatic artery proper?

Answer 2

supplies the liver with arterial blood

Question 3

where is the hepatic artery proper derived from?

Answer 3

coeliac trunk

Question 4

what does the hepatic portal vein supply the liver with?

Answer 4

supplies the liver with deoxygenated blood, carrying nutrients absorbed from the small intestine

Question 5

what does hepatic portal vein carry?

Answer 5

carrying nutrients absorbed from the small intestine

Question 6

what is the function of the hepatic portal vein in terms of the liver parenchyma?

Answer 6

This is the dominant blood supply to the liver parenchyma and allows the liver to perform its gut-related functions, such as detoxification

Question 7

how is venous drainage of the liver achieved?

Answer 7

achieved through three hepatic veins

Question 8

where do the 3 hepatic veins drain into?

Answer 8

inferior vena cava

Question 9

what is the parenchyma of the liver innervated by?

Answer 9

The parenchyma of the liver is innervated by the hepatic plexus

Question 10

what does the haptic plexus contain?

Answer 10

contains sympathetic (from the coeliac plexus) and parasympathetic (vagus nerve) nerve fibres

Question 11

where do the sympathetic and parasympathetic fibres enter the liver at?

Answer 11

These fibres enter the liver at the porta hepatis

Question 12

what course of travel do the sympathetic and parasympathetic fibres follow?

Answer 12

follow the course of branches of the hepatic artery and portal vein

Question 13

what is Glisson’s capsule?

Answer 13

the fibrous covering of the liver

Question 14

what is Glisson’s capsule innervated by?

Answer 14

innervated by branches of the lower intercostal nerves

Question 15

what does distension of the Glisson’s capsule result in?

Answer 15

results in a sharp, well localised pain

Question 16

where do the lymphatic vessels of the liver drain into?

Answer 16

hepatic lymph nodes

Question 17

where do the hepatic lymph nodes lie?

Answer 17

These lie along the hepatic vessels and ducts in the lesser omentum

Question 18

where do the hepatic lymph nodes empty into?

Answer 18

the coelic lymph nodes

Question 19

what is a percutaneous liver biopsy?

Answer 19

A procedure used to obtain a sample of liver tissue

Question 20

how do you carry out a percutaneous liver biopsy?

Answer 20

A needle is inserted through the skin to access the liver

Question 21

when is a percutaneous liver biopsy required? give some examples of clinical scenarios

Answer 21

Abnormal LFTs of unknown cause.
Hepatitis C
Other liver conditions (such as Hereditary Haemochromatosis and Autoimmune Hepatitis)
Following liver transplantation

Question 22

why is percutaneous liver biopsy used in hepatitis C?

Answer 22

Assessment for severity of liver fibrosis and disease progression

Question 23

how is the liver located in the during a percutaneous liver biopsy?

Answer 23

During the procedure, the liver is located via ultrasound.

Question 24

what is injected and where during a percutaneous liver biopsy?

Answer 24

Local anaesthetic is injected on the mid-axillary line, where on percussion there is dullness

Question 25

what do you ask the patient to do during a percutaneous liver biopsy?

Answer 25

The patient is asked to deeply expire (avoiding damage to the lungs), and the needle biopsy is taken during held expiration

Question 26

what do you do when a patient has an abnormal clotting?

Answer 26

If a patient has abnormal clotting (a contraindication for the procedure), a transvenous liver biopsy can be attempted.

Question 27

what does a transvernous liver biopsy involve?

Answer 27

This involves cannulating the internal jugular vein, and passing the biopsy needle through to the hepatic veins, allowing for a biopsy sample to be taken.