Abdominal Vasculature - Part 7 Flashcards
Thrombus
Stationary blood clot along the wall of a blood vessel, frequently causing vascular obstruction
What causes IVC thrombus? (7)
Extrinsic compression from
- Tumours
- sarcomas —> renal or adrenal - Lymph nodes
- AAA
- Polycystic kidneys
- Trauma
- DVT from lower extremities
- Retroperitoneal fibrosis
What is a sign of IVC thrombus?
Bilateral leg swelling
- this is not a cause
What is bilateral leg swelling caused by with IVC thrombus?
Pooling of blood
IVCFs
Inferior Vena Cava Filters
Inferior Vena Cava Filters
Devices that can be deployed into the IVC to block the passage of thrombi from the lower extremities and pelvis into the lungs
What do IVCFs help with?
In preventing embolization
What is the most common cause of IVC thrombosis?
The presence of an un-retrieved IVC filter
Renal artery stenosis
Narrowing of a renal artery
- occurs slowly over time
What forms in renal artery stenosis?
Collateral vessels
- supply the kidney
What does collateral vessels lead to in a renal artery stenosis?
Secondary hypertension
What is the most common cause of renal artery stenosis?
Atherosclerosis
What segment of the renal artery is most common for a stenosis?
The proximal segment
What is the second most common cause of renal artery stenosis?
FMD
- fibromuscular dysplasia
What indicates a renal artery stenosis?
Anything larger than a 3.5 ratio renal artery to aortic ratio
What is tardus parvus an indicator of?
An upstream significant renal artery stenosis
What do renal ratios do?
Assess the main renal artery for stenosis
- must be compared to the proximal aorta flow using a ratio between the aorta and the renal artery
What is the formula for the renal ratio?
Renal artery / aorta
How high can the renal artery PSV be for it still to be considered normal?
180cm/s
Where do you measure on the aorta PSV for the renal ratio?
Just above the renal artery takeoff
Where do you measure on the renal artery for the renal ratio? (2)
- At the origin
- sometimes covered by gas
Or
- Measure the PSV of the distal renal artery at the hilum
- easy to identify
RI
Resistive indices
When is resistive indices used?
What a renal artery stenosis is suspected
If a renal artery stenosis is suspected, what should you want to assess?
The intrarenal vessels
