Diagnostic Ultrasound - Abdomen and Pelvis

Liver Transplant Hepatic Artery Stenosis/Thrombosis
Diagnoses: Liver
IMAGING
• Hepatic artery stenosis
○ Elevated peak systolic velocity at anastomosis > 200
cm/sec
○ Parvus tardus waveforms in intrahepatic arteries
– Acceleration time > 0.08 sec
– Resistive index < 0.5
• Hepatic artery thrombosis
○ No detectable flow in hepatic artery with color or
spectral Doppler
○ May see "collateral transformation of hepatic artery"
– Tortuous collateral arteries in porta hepatis and
parvus tardus intrahepatic arterial waveforms
PATHOLOGY
• Hepatic artery stenosis
○ Stenosis occurs at anastomosis
○ Usually occurs at > 3 months post transplant
• Hepatic artery thrombosis
KEY FACTS
○ May occur < 15 days or years after transplant
○ Risk factors: Difference in hepatic artery caliber between
donor and recipient, prolonged graft ischemia time, ABO
blood group incompatibility, CMV infection, acute or
chronic rejection, hypercoagulable state, sepsis
CLINICAL ISSUES
• Hepatic artery stenosis
○ May be related to injury at time of surgery or disruption
of vasa vasorum with ischemia of hepatic artery
• Hepatic artery thrombosis
○ Most common immediate vascular complication (2-12%)
○ Complete occlusion of hepatic artery in early transplant
period leads to liver failure
– Up to 75% of patients with hepatic artery thrombosis
require retransplantation
○ Biliary ducts in liver transplants supplied only by artery
– Hepatic artery thrombosis can result in biliary
ischemia, bilomas, bile lakes
(Left) Graphic depicts focal
stenosis ſt of the hepatic
artery anastomosis in a liver
transplant. (Right) Spectral
Doppler evaluation of the
main hepatic artery near the
site of anastomosis shows an
elevated hepatic artery
velocity of 236 cm/sec ſt,
which is consistent with a
stenosis.
(Left) Angiographic image in
the same patient confirms a
focal stenosis in the
hepatic artery at the level of
the anastomosis. (Right)
Volume-rendered CT
angiogram of the aorta and
celiac artery shows an abrupt
termination ſt of the hepatic
artery, consistent with hepatic
artery thrombosis in a patient
with a liver transplant.
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