Hepatoportal Abdominal Doppler Flashcards
spectral Doppler waveforms and velocity measurements of
Main, right and left portal vein Right, middle and left hepatic veins Splenic vein Superior mesenteric vein Inferior vena cava Hepatic artery proper (angle-corrected velocity)
normal findings of portal veins
Hepatopetal (toward liver)
Velocity typically of 15-18 cm/s
Varies with respiration and cardiac pulsation
IVC and Hepatic veins
Phasic throughout respiratory and cardiac cycles
Increased diameter in patients with congestive heart failure
Splenic Vein
Flow is toward liver
Monophasic with slight pulsatility, similar to portal veins
Portal hypertension
Abnormal increase in portal venous pressure due to obstruction of blood flow through liver
Portal vein flow portal hypertesnion-first
First becomes monophasic, no undulations
Portal vein flow portal hypertesnion-second
As worsens, becomes biphasic (some reversal)
In worst cases of portal hypertension
becomes hepatofugal (away from liver)
what may also be seen in portal venous hypertension
May also see intrahepatic aterial-portal venous shunting
what modalities are used in portal hypertension
Ultrasound Doppler is accurate in assessing anatomy and flow direction
MR angiography is superior to U/S in assessing patency of portal vein and surgical shunts, and detecting varices
Sonographic signs of portal hypertension
Ascites Splenomegaly Varices Portosystemic venous collaterals Portal vein diameter >13mm Increased hepatic artery flow (arterialization)
causes of portal hypertension
Cirrhosis due to alcohol abuse or hepatitis are most common
Complications of portal hypertension
Primary is gastrointestinal bleeding from ruptures esophogeal and gastric varices
what are the five major sites of portosplenic venous collaterals
Gastroesophogeal junction Paraumbilical vein Splenorenal and gastrorenal Intestinal Hemorrhoidal
TIPS
Transjugular intrahepatic portosystemic shunt
what is TIPS used to treat
Used to treat portal hypertension that usually involves varices with gastrointestinal bleeding
where do shunts usually run
Usually between right portal and right hepatic veins
Reroutes blood away from liver, from the portal vein, through the stent, into hepatic vein, back to the heart
Normal post TIPS Doppler findings
High velocity, turbulent flow through stent
Hepatofugal flow in intrahepatic portal veins
Increased hepatic artery peak systolic velocity
Complications of portosystemic shunts
Stent stenosis or occlusion
Hepatic vein stenosis
Direct signs of portosystemic shunt complications
No flow Abnormal peak shunt velocity Low velocity in main portal vein Reversal of hepatic vein flow Hepatopedal intrahepatic portal vein flow
Indirect signs of portosystemic shunt complications
Reaccumulation of ascites
Reappearance of collaterals
Recanalization of paraumbilical vein
Causes of portal vein thrombosis Adults
Trauma Sepsis Malignancy (HCC, metastases, pancreatic carcinoma) Splenomegaly / splenectomy Chronic pancreatitis Hypercoagulable states
causes of portal vein thrombosis children
Umbilical vein catheterization
Omphalitis
Neonatal sepsis
Acute dehydration
Budd Chiari
Rare syndrome where there is occlusion of the lumen of the hepatic veins and/or the IVC
Budd Chiari Doppler Findings
Flow in IVC and/or hepatic veins changes from phasic continuous, reversed, turbulent or absent
Portal vein flow may be either slowed or reversed
