Diagnostic ultrasound ( PDFDrive )

CHAPTER
18
Organ Transplantation
Derek Muradali and Tanya Punita Chawla
SUMMARY OF KEY POINTS
• To perform an ultrasound assessment of a transplanted
organ, the sonographer should be aware of the surgical
technique used including the type and location of vascular
and nonvascular anastomoses.
• Gray-scale parenchymal changes often relect the vascular
status of the allograft (e.g., echogenic intraluminal material
within a dilated biliary tree of a transplanted liver may
result from sloughing of the biliary epithelium as a result of
hepatic arterial narrowing or thrombosis).
• Evaluation of the tissues surrounding the allograft is just as
important as assessment of the allograft itself.
• Any presumed cyst identiied in the parenchyma of the
allograft or in the region of the hilum should be assessed
with color Doppler to exclude the possibility of a
pseudoaneurysm.
• The criteria for arterial stenosis are similar with different
allografts in that high-turbulence low is detected at the
region of narrowing with a distal tardus-parvus waveform.
• When assessing transplanted veins (portal vein, renal vein,
inferior vena cava), a threefold to fourfold velocity increase
at the site of stenosis relative to the prestenotic segment
on spectral interrogation represents a hemodynamically
signiicant stenosis.
• Elevated resistive indices may be of limited value
depending on the allograft being interrogated—in renal
transplants they are a nonspeciic marker of renal
dysfunction; in liver transplants they are of no clinical
relevance; and in pancreatic transplants that are failing, the
resistive indices may not be elevated owing to the lack of
a pancreatic capsule.
CHAPTER OUTLINE
LIVER TRANSPLANTATION
Surgical Technique
Normal Liver Transplant Ultrasound
Biliary Complications
Biliary Strictures
Bile Leaks
Recurrent Sclerosing Cholangitis
Biliary Sludge and Stones
Dysfunction of the Sphincter of Oddi
Arterial Complications
Hepatic Artery Thrombosis
Hepatic Artery Stenosis
Elevated Hepatic Arterial Resistive
Index
Hepatic Artery Pseudoaneurysms
Celiac Artery Stenosis
Portal Vein Complications
Inferior Vena Cava Complications
Hepatic Vein Stenosis
Extrahepatic Fluid Collections
Adrenal Hemorrhage
Organ transplantation is the preferred treatment for patients
with end-stage liver, renal, and pancreatic disease. Patients
with fulminant liver failure have no other treatment option
apart from orthotopic liver transplantation. Although patients
with renal or pancreatic failure may be treated with dialysis or
Intrahepatic Fluid Collections
Abscess Versus Infarct
Intrahepatic Solid Masses
RENAL TRANSPLANTATION
Surgical Technique
Normal Renal Transplant Ultrasound
Gray-Scale Assessment
Doppler Assessment
Abnormal Renal Transplant
Parenchymal Pathology
Acute Tubular Necrosis and Acute
Rejection
Chronic Rejection
Infection
Prerenal Vascular Complications
Arterial Thrombosis
Renal Artery Stenosis
Venous Thrombosis
Renal Vein Stenosis
Postrenal Collecting System
Obstruction
Arteriovenous Malformations and
Pseudoaneurysms
Fluid Collections
PANCREAS TRANSPLANTATION
Surgical Technique
Venous Drainage
Arterial Supply
Normal Pancreas Transplant Ultrasound
Role of Contrast-Enhanced Ultrasound
Abnormal Pancreas Transplant
Thrombosis
Arteriovenous Fistula and
Pseudoaneurysms
Rejection
Pancreatitis
Fluid Collections
Miscellaneous Complications
POST TRANSPLANT
LYMPHOPROLIFERATIVE
DISORDER
Treatment Options
medical therapy, their long-term survival and quality of life are
far superior with organ transplantation. Recent improvements
in grat survival have been attributed to a combination of better
donor-recipient matching, 1 more efective immunosuppressive
therapy, improvements in surgical technique, and early recognition
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