Liver (test 3) Flashcards
What cavity does the liver reside in?
Intraperitoneal cavity
What is one of the largest organs in the body?
Liver
What does the liver do?
Metabolic processes. Filters and detoxifies blood. Regulates blood volume. Dispose old RBC, creates new RBC. Processes blood from bowel. Converts glucose into glycogen and stores it. Stores minerals. Produces proteins.
What is bile?
Major by-product of broken down RBC.
Emulsifier of fat that aids in digestion.
Where does the liver process blood from the bowel?
Via the portal system.
What does the liver convert?
Converts glucose to glycogen and stores it in the liver.
What does the liver do when the body needs energy quickly?
Converts the glycogen back to glucose and returns it to the bloodstream.
What minerals are stored in the liver?
Copper
Iron
Vitamins (A, D and B12)
What does the liver produce that is necessary for blood clotting?
Proteins
What are the 4 quadrants?
Rt upper
Rt lower
Lt upper
Lt lower
What quadrant (s) does the liver lay in?
Rt upper, and small amount in the Lt upper.
What is the dual blood supply in regards to liver?
Hepatic artery supplies 30% of blood flow (oxygen-rich)
Portal vein supplies 70% blood flow (nutrient rich) from GI tract.
What vessels make the hepatic flow?
Hepatic artery and portal vein
What type of blood does the hepatic artery supply?
Oxygen-rich
What type of blood does the portal vein supply?
Nutrient-rich
What comprises the portal triad?
Hepatic artery
Portal Vein
Bile duct
What is the porta hepatis?
Transverse fissure between lobes where the portal vein and hepatic artery enter the liver, and bile duct exits
What vessels enter the liver, which exit?
Hepatic artery and portal veins enter.
Bile duct exits
What vessels make up the main portal vein? (MPV)
Splenic vein and superior mesenteric vein.
Where does the portal vein lie in relation to IVC?
Anterior to the IVC
What happens to the MPV when it enters the porta hepatis?
Divides into right portal vein, and left portal vein
What characteristics does the right portal vein have?
Larger
Posterior and caudal (toward head)
Divides into anterior and posterior branches
What characteristics does the left portal vein have?
Anterior and cranial.
Divides into the medial and lateral branches.
What characteristics does the portal vein have?
NO valves.
Bright, echogenic walls due to collagenous tissue.
Course intra-segmentally (within liver segments)
What is hepatopetal?
Flow that is going toward the liver
What is hepatofugal?
Flow going away from the liver
What are the main hepatic veins?
Right (RHV), Middle (MHV), and Left (LHV) hepatic veins
What veins are the primary outflow for the liver?
The hepatic veins
Where do the hepatic veins drain?
Drain into the IVC, near right atrium
What is a normal hepatic Doppler signal?
Pulsatile
Where does the common hepatic artery arise off?
The celiac axis
When does the common hepatic artery become the proper hepatic artery?
Once it courses over the anterior-superior edge of the pancreas and gives rise to the gastro duodenal artery
Where does the hepatic artery end?
the level of the porta hepatis
Does the hepatic artery divide?
Divides into the right and left branches in the liver
Where does the hepatic artery lie?
Anteromedial to the portal vein
What are hepatoportal exam indications?
Portal Hypertension* Cirrhosis Thrombosis of portal, splenic, SMV. TIPS evaluation. Budd Chiari syndrome. Acute abdominal pain. Ascites of unknown cause. Pre-Post intervention. Elevated D-dimer
What are hepatoportal risk factors?
Chronic liver disease
Heart disease resulting in elevated right-sided heart pressures
What are chronic liver diseases?
Viral hepatitis, chronic hep B or C.
Alcoholic liver disease.
Metabolic and genetic disorders
What are some heart diseases leading to elevated right-sided heart pressures?
CHF
Tricuspid regurgitation.
How to assess liver vessels in B-mode?
Extra- and intra-hepatic portal veins.
Hepatic veins.
IVC
How to assess liver vessels with Doppler and velocities?
MPV, RPV, LPV. RHV, MHV, LHV. SV. (splenic vein) SMV. IVC. Proper hepatic artery.
What are some other assessment options?
Size and echogenicity. Masses, cysts. Spleen size. Ascites presence. MPV diameter during quiet respirations.
What is the diameter for the portal vein?
Less then or equal to 13mm.
What flow directions are for the portal triad vessels?
Towards liver= hepatic artery, portal vein
Away= bile duct
What is the diameter for splenic vein and SMA?
up to 10 mm
How do you distinguish the hepatic artery from portal vein?
Artery is smaller in diameter
What is the diameter of the IVC?
15mm-25mm
What is unique about the liver veins?
They are mostly pulsatile in waveform
What happens to the diameter and velocity during inspiration for portal, splenic and SMV?
Diameter increases
Velocity decreases
What happens to the velocities for portal, splenic and SMV during expiration?
Velocities all increase
What is ascites?
Effusion and collection of serous fluid in abdominal cavity.
Legs usually swell
What is portal hypertension?
Elevated portal venous pressure due to impedence of blood flow through liver.
Causes divided into 3 categories:
pre, intra, post-hepatic flow
What is the most common etiology for portal hypertension?
Cirrhosis caused by hepatitis C
What is the primary complication of portal hypertension?
GI bleeding from ruptured esophageal and gastric varices.
What are duplex findings of portal hypertension?
PV >13mm. SV and SMV >10mm. Decreased respiratory variation ( Pv, SV) Decreased PV velocity. Hepatofugal in PV/SV. Collaterals. Ascites. PV obstruction. Increased hepatic artery flow. Splenomegaly.
What is TIPS treatment?
Shunt
Lowers pressure in portal venous system.
Stent is placed to connect one PV with HV.
Re-routes blood away from liver to HV back to heart.
TIPS assessment on duplex
Velocities ad flow direction: MPV, PV end of shunt, mid shunt, HV end of shunt, IVC or outflow HV.
Flow direction: adjacent intrahepatic PV, SV, SMV.
Assess for ascites and varices.
What are normal duplex findings for TIPS?
MPV=hepatofugal. Flow directed towards HV. Color fill wall-to-wall in stent. Stent velocities=90-190 cm/s. MPV, Hep artery velocities increase from pre-TIPS
TIPS stenosis
PSV<50 in stent.
PSV <30 in MPV.
Increase in stent velocity >200.
Velocity change of >50 in stent vs previous exam.
>50 velocity in stent compared to other segment.
Recurrent ascites, varices, splenomegaly.
Change in flow direction in PV.
Retrograde flow in HV
What does portal vein thrombosis result from?
Status from cirrhosis and portal hypertension.
Pancreatitis, appendicitis, diverticulitis.
Hypercoaguable state.
Surgery.
Trauma.
Abdominal malignancy.
What are duplex findings for portal venous thrombosis?
PV diameter increase: >15mm=acute >23 mm with intraluminal echoes=tumor thrombosis. Non-visualized PV. No color in obstructed PV. Gallbladder varices. Increased hepatic arterial flow.
What is budd-chiari syndrome?
HV outflow obstruction from thrombus or tumor.
Presence of RUQ pain, jaundice, ascites, hepatomegaly, liver function abnormalities.
May be cause be IVC stenosis or occlusion cephalad to HV.
Duplex findings of Budd-Chiari syndrome?
IVC or HV dilation with intraluminal echoes. Absence of flow in IVC or HV. Hepatomegaly, Sluggish or retrograde flow in PV. Splenomegaly. Stenosis or occlusion of HV or IVC. Ascites. Collaterals.
Duplex findings of CHF
Dilation with hepatoportal venous system and IVC.
PV markedly pulsatile.
HV- highly pulsatile and demonstrates flow reversal during systole.
RHV diameter increase to >9mm
