renal artery Flashcards
key symptoms for renal artery stenosis
- HTN
2. renal insufficiency
what percentage of htn is caused by renal artery stenosis
5%
How to prep for renal artery duplex
- fast for 12 hrs to decrease bowel gas shadowing
2. no medications
interrogated portions of the renal artery
- main renal artery (origin, prox, mid, distal)
2. segmental arteries (upper, mid, lower poles)
classic appearance of a normal main renal artery waveform
- rapid systolic upstroke
2. continuous forward diastolic flow
criteria for renal artery stenosis
Direct evaluation 1. increased peak systolic velocity (>180-200 cm/sec) 2. Renal-aortic ratio (RAR) > 3.5 Indirect 3. abnormal segmental waveforms 4. RI >0.7
can stenosis of an accessory renal artery be the cause of HTN
no
what do you look for during evaluation of the segmental/hilar arteries
check for tardus parvus waveforms
what can a segmental renal artery tardus parvus waveform indicate
occult stenosis in main renal artery vs. possible stenosis from a duplicate renal artery if other segmental arteries are normal
normal waveform of a segmental/intrarenal artery
- rapid systolic upstroke 90 degrees to baseline
- low resistance
- early systolic compliance peak (looks like a beak)
are tardus parvus waveforms always seen in patients with Renal artery stenosis
No
in what settings are tardus parvus waveforms not seen
they are not seen in non-compliant vessels
- diabetes (calcifications)
- very bad atherosclerosis
- old patients
how do you calculate resistive index in renal artery
RI = PSV-EDV/PSV
what is a normal RI in renal artery
less than 0.7
In-stent re-stenosis criteria for renal artery stenting
RAR > 2.5-3.2
PSV > 240
hilar waveforms unchanged (still TP waveform) or changing for the worse
