Post-Intervention and Grafts Flashcards

When performing duplex surveillance of a femoral-femoral crossover bypass graft, which vessel should be evaluated as the primary inflow source?

Answer: The donor common iliac and external iliac artery ipsilateral to the graft origin

The donor iliac system is the inflow for a femoral-femoral crossover graft, so iliac stenosis on the donor side directly threatens graft patency.

A synthetic aortobifemoral bypass graft is being evaluated. Flow in the right limb is triphasic and normal. The left limb shows monophasic, low-velocity waveforms. The most likely cause is:

Answer: Stenosis or occlusion of the left graft limb or its outflow

Asymmetric waveforms between graft limbs indicate a unilateral problem; monophasic low-velocity waveforms in the left limb suggest stenosis or occlusion within that limb or distal to it.

During duplex evaluation of an infrainguinal vein graft, a segment with absent color fill and no detectable Doppler signal is identified. What is the most likely diagnosis?

Answer: Focal graft thrombosis or occlusion

Absence of color fill and Doppler signal in a graft segment indicates focal thrombosis, which may be amenable to thrombolysis or surgical revision if identified promptly.

Which of the following is the MOST important parameter to document when performing post-angioplasty surveillance of the superficial femoral artery?

Answer: PSV at the treatment site, PSV ratio, and waveform character

Post-SFA angioplasty surveillance should document PSV at the treated segment, PSV ratio versus proximal normal SFA, and waveform character to classify residual or recurrent stenosis.

A patient undergoes carotid artery stenting (CAS). At 1-month follow-up duplex, the ICA PSV within the stent is 180 cm/s with an ICA/CCA ratio of 2.2. How should this be categorized?

Answer: Moderate in-stent restenosis (approximately 50%), requiring close surveillance

ICA PSV 125–300 cm/s with ICA/CCA ratio 2.0–4.0 after CAS suggests moderate restenosis (approximately 50%), which warrants intensified duplex surveillance intervals.

After EVAR, a type I endoleak at the proximal neck is identified by duplex. What is the typical color flow direction within the endoleak channel?

Answer: Antegrade systolic flow from the aortic lumen into the perigraft space

Type I endoleaks involve direct communication between the aortic lumen and the aneurysm sac, producing antegrade pulsatile arterial flow into the perigraft space during systole.

A patient with prior angioplasty of the right renal artery presents with recurrent hypertension. Duplex shows a peak renal artery PSV of 220 cm/s and a RAR (renal-aortic ratio) of 4.5. What does this indicate?

Answer: Significant recurrent or residual renal artery stenosis (>60%)

A renal artery PSV >200 cm/s combined with a RAR >3.5 meets duplex criteria for significant (>60%) renal artery stenosis, indicating restenosis after angioplasty.