Diagnostic Ultrasound - Abdomen and Pelvis

Transplant Renal Artery Thrombosis
Diagnoses: Kidney Transplant
TERMINOLOGY
• Occlusion of transplant renal artery secondary to thrombus
IMAGING
• Absence of blood flow in main renal artery
• Diffuse absence of parenchymal perfusion on color or
power Doppler
• If involving accessory renal artery
○ Segmental wedge-shaped peripheral area of decreased
color flow
• US is first-line imaging modality for complications of renal
transplantation
• Optimize color and spectral Doppler settings for slow flow
TOP DIFFERENTIAL DIAGNOSES
• Transplant renal vein thrombosis
• Acute rejection/acute tubular necrosis
• Hyperacute rejection
KEY FACTS
CLINICAL ISSUES
• Rare < 1%
• Abrupt onset of oliguria, decreased function, pain and
swelling of allograft
• Poor prognosis, graft loss is usual when single main artery is
thrombosed
○ Transplant nephrectomy
○ Thrombectomy or thrombolysis rarely successful unless
diagnosis made early
• Accessory or segmental arterial thrombosis: Ischemia and
subsequent atrophy
DIAGNOSTIC CHECKLIST
• Severe acute rejection or tubular necrosis may cause
propagating small vessel thrombosis resulting in infarction
and mimic transplant renal artery thrombosis (TRAT)
• Urgent finding requiring prompt communication
(Left) Longitudinal color
Doppler US in the 1st day after
renal transplantation shows
no color flow in the allograft
ſt secondary to early
thrombosis in a
hypercoagulable patient.
(Right) Longitudinal pulsed
Doppler ultrasound of the
same patient shows no
intrarenal arterial flow. Noise
ſt was transmitted to the
kidney.
(Left) Transverse color
Doppler ultrasound of a
thrombosed recent renal
transplant shows an
edematous allograft st with
no internal color flow. The
iliac artery ſt is patent.
(Right) Longitudinal color
Doppler ultrasound shows a
renal allograft with segmental
ischemia of the lower pole ſt
secondary to thrombosis of an
accessory renal artery.
Absence of color flow is noted
in the lower 1/2 of the
allograft.
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