Misc Conditions Flashcards
What is the size range of the IVC?
Variable 1.5 - 2 cm (never exceed 2.5)
How many layers comprise the IVC?
Three
Is the IVC intra or retroperitoneal?
Retroperitoneal
Where is the IVC positioned?
Anterior to the spine, right lateral to the aorta
What are findings of thrombus in IVC?
IVC enlargement, absence of flow, material noted within lumen
Why is acute thrombus often overlooked?
It may be anechoic (acute thrombus is hypoechoic/chronic thrombus is hyperechoic)
What is an IVC filter used?
To trap emboli that could be traveling upstream
How is the IVC filter evaluated?
Proper placement and to assess for complications such as IVC perforation and to prevent PE
How does an umbrella filter appear?
Hyperechoic
How does a tumor thrombus (i.e. renal cell carcinoma) appear?
Aggressive mass invading the renal vein and IVC
How does the intrahepatic IVC appear with cardiac failure?
5.5 cm dilatation or more
What could be confused with thrombus in IVC?
Slow, sluggish blood flow
What is an anotomical variation of the IVC?
Double vena cava
What is portal vein thrombosis and where is it seen?
A developed clot within portal vein seen in HCC, portal hypertension, pancreatitis and pregnancy
What occurs with partial thrombosis?
There is flow within the vein
Besides Hep B / C and cirrhosis (including primary biliary), what are indications for a liver transplant?
Budd-chiari, acute liver failure, chronic active autoimmune hepatitis, primary sclerosing cholangitis, primary benign/malignant neoplasms
What conditions of liver are used for transplants?
Cadaveric allograft (including lobar transplant) and living related donor (also lobar)
What types of anastomoses are there in liver transplantation?
Suprahepatic, infrahepatic vena cava, hepatic artery and portal vein (as well as biliary anastomosis)
What must liver donors have done in addition to explantation?
Have a cholecystectomy
What is OLTX and LDLT(X)?
Orthotopic liver transplantation (cadaveric)
Living Donor Liver transplantation
What is the advantage of OLTX?
It doesn’t involve much anastomoses
Which portion of the liver is usually taken for grafting?
Right lobe
After you estimate liver and spleen size, what checklist must be done (pre-liver transplant)?
Patency of IVC, portal vein (length/dia of extrahepatic portion), anatomical variation of HA, collaterals portal to systemic, any hepatic mass or ascites quantity
What does ultrasound show in a recipient’s liver parenchyma with cirrhosis changes?
Nodular contours, parenchymal inhomogeneity, right-lobe atrophy, and hypertrophy of lateral segment/caudate lobe
What does cirrhosis cause?
Narrowing of the hepatic veins and loss of the normal phasic waveform, caudate lobe can enlarge and surround IVC
How does blood flow show on a normal liver transplant?
Brisk systolic upstroke and continuous diastolic flow during spectral doppler evaluation
What does spectral doppler show on a normal liver transplant?
Continuous, mildly undulating hepatopedal flow and hepatic veins show hepatofugal flow (RI range from 0.5-0.7)
What is post-op evaluation of liver parenchyma?
Parenchymal echogenicity
What is post-op evaluation of liver perihepatic spaces?
Ascites, hemorrhage and fluid collections
What is post-op evaluation of liver biliary system?
Ductal dilation and intraluminal filling defects
What is post-op evaluation of liver vasculature?
Hepatic A/V’s, portal vein, IVC patency, arterial/venous waveforms and RI’s, anastomoses (focal color aliasing/elevated velocities)
What are 2 complications in LDLT?
Acute rejection and vascular complications
What is the range of LDLT acute liver rejection and how does it compare cadaveric?
17% - 40% and is lower (unknown)
What are U/S findings of coarsed, heterogeneous parenchyma found in the first stages of liver transplant?
Recurrent cirrhosis, ischemia and necrosis
What are U/S findings of focal lesion in the first stages of liver transplant?
Neoplasm, infarct, abscess, and ductal abnormality
What are U/S findings of elevated resistive indices in the first stages of liver transplant?
Extrinsic compression, parenchymal disease, and venous outflow obstruction
What are U/S findings of decreased resistive indices in the first stages of liver transplant?
Hepatic artery stenosis, advanced aortoiliac atherosclerosis, median arcuate ligament compression
What are U/S findings of hepatic venous phasicity loss in the first stages of liver transplant?
Advanced parenchymal disease, rejection, and caval anastomotic stenosis
What are vascular complications of LDLT and what percentage does it make up?
Thrombosis, stenosis of the hepatic artery/veins, portal veins, and pseudoaneurysms making up 9% of liver transplants (most common)
Which group of people are more likely to have vascular problems in LDLT?
Pediatric (small size of vessels)
What is the most common vascular complication of liver transplantation?
Hepatic artery thrombosis
What are complications in LDLT?
Acute rejection, vascular complications and biliary complications
What is the most common vascular complication of liver transplantation?
Hepatic artery thrombosis (requiring revascularisation/retransplantation)
What are U/S findings of hepatic artery inflow compromise?
Intrahepatic tardus parvus (slow upstroke/low-res flow
What are findings of significant stenosis?
A focal high velocity jet in the hepatic artery in excess of 200 cm/s or greater than 3X the velocity in prestenotic HA
What does spectral show with hepatic artery stenosis?
A delayed systolic upstroke and rounding of the systolic peak consistent w/tardus-parvus due to anastomotic stenosis in the HA
What will show with HA pseudoaneurysm post biopsy?
Color flow will show a marginated, round lesion with internal flow consistent with a pseudoaneurysm
When do portal vein abnormalities occur in LDLT?
1% to 3% and are uncommon
What is a portal vein LDLT abnormality and how does is appear?
Acute portal vein thrombus which appears moderately hypoechoic or isoechoic w/absence of Doppler signal (diffuse low velocity/focal elevated velocities @ anastomosis are signs of portal vein stenosis)
How can color flow appear in the portal vein following the liver transplant?
Swirling due to helical flow and can indicate the vessels kinking or significant vessels size mismatch
What percentage of liver transplants have biliary complications?
24% with a significant cause of post-transplant morbidity and mortality
What type of liver transplant are more common with biliary complications?
LDLT including bile leaks, strictures, calculi or sludge, dysfunction of the sphincter of Oddi
What kinds of collections can occur after LDLT?
Perihepatic fluid collections and abscesses
How do intra-hepatic conditions appear on U/S?
Cystic/solid masses without internal vascularity (may represent seromas, hematomas or infarction)
What indicates a hematoma?
Complex lesions w/mass effect on surrounding structures (U/S detects collections and can guide drainage)
What type of post-transplant malignancies can occur?
4% - 5% develop malignant tumors with increased incidence of lymphoma (mostly non-Hodgkin’s) and recurrent HCC
