Module 7 Liver Vasculature Flashcards
The evaluation of the portal system is a common procedure often related to what?
Chronic liver disease and cirrhosis of the liver
Liver vasculature evaluation includes the evaluation of what? 5
- Hepatic veins
- Portal veins
- Hepatic Artery
- IVC
- Collaterals
Some of the vascular disorders we will look at are what? 3
- Portal hypertension
- Shunts/Stents
- Transplants
What are two types of portal hypertension?
- Portal vein thrombosis
- Hepatic vein thrombosis
How many major hepatic veins are there?
Three
Where do the MHV and the LHV typically join?
Before the IVC
Which Hepatic vein is typically duplicated?
Left hepatic veins
What do the hepatic veins drain into?
The IVC and become larger in diameter on their approach
What does Hepatic Vein waveforms look like typically?
Respirophasic and pulsatile
Why do we evaluate the hepatic veins?
We assess for patency or distension
What does this image demonstrate?
The hepatic veins draining into the IVC
What does the portal veins drain?
Blood from the bowel and spleen to the liver
How much blood does the portal veins supply to the liver?
Approximately 75%
The MPV is comprised of what?
Splenic and superior mesenteric veins
The MPV enters the liver through what?
The porta hepatis
When describing flow in the portals and hepatic veins we use what terms?
- Hepatopetal
- Hepatofugal
What does hepatopetal mean?
Towards the liver
What does hepatofugal mean?
Away from the liver
Portal veins have a low velocity normally, what is the range?
16-40 cm/s (variable- depends on source)
What is the flow relatively for portal veins post prandial?
Flow increase post prandial
The normal MPV diameter should be what?
Less than 13 mm
What does this image demonstrate?
MPV
What does this image demonstrate?
LPV
What does this image demonstrate?
RPV
How much blood does the hepatic artery supply to the liver?
25%
What kind of path does the Hepatic artery have?
tortous
Where is the proximal hepatic artery seen?
At the celiac axis
Where is the distal hepatic artery seen? 2
- Intercoastal
- MPV and RPV
Where is the distal hepatic artery seen?
- Intercoastal
- MPV and RPV
What is the resistance like in the hepatic artery?
Low resistance
Is there normally spectral broadening in the hepatic artery?
Yes, because the vessel is quite small
What is the velocities of the Hepatic artery?
Variable so RI is used to assess for pathology
What is the normal Resistive index?
0.5 - 0.7
What is the IVC formed from?
Iliac veins
Where is the IVC located?
Anterior to the spine and right of the aorta
What is the size of the IVC?
Variable, greater then 2.5 cm considered dilated
What does the IVC spectral trace look like? 3
- Spontaneous waveform?
- pulsatile proximal
- Phasic distally
What is the IVC spectral trace influenced by?
Heart and respiration
What categories can portal hypertension be categorized into? 3
- Pre- hepatic
- Intrahepatic (most common)
- Post hepatic
What is the leading cause of portal hypertension?
Cirrhosis
What is the leading cause of cirrhosis?
Hepatitis C followed by alcoholism
What are the signs and symptoms of portal hypertension? 5
- Jaundice
- Abnormal LFT
- Ascites (increased abdominal girth)
- Splenomegaly
- GI bleed
What are two types of GI bleeds?
- Hematemesis (vomiting blood)
- Melena (dark starry stools)
For a portal hypertension physical examination the patient can present with what? 2
- Caput medusae (dilated abdominal wall veins)
- Hepatic encephalopathy (confusion due to poor liver function)
What is Pre-hepatic obstructions?
- Pathology that occurs to blood flow before it enters the liver (inflow)
What are some examples of pre-hepatic obstruction? 4
- Portal or splenic vein thrombosis
- Portal or splenic vein invasion
- Extrinsic compression by tumor
- Inflammation of the pancreas (pancreatitis)
Portal vein thrombosis can be caused by what? 5
- Cirrhosis (20%)
- Malignancies (20%)
- Hypercoagulable states
- Intra- abdominal inflammation/ infection
- Trauma (From surgery)
Chronic PHT may be asymptomatic or symptomatic?
Asymptomatic