RVT Post-Intervention and Grafts 2

Question 1

Which PSV ratio across a graft stenosis is most consistent with a hemodynamically significant (>50%) lesion?

Accepted Answer

PSV ratio >2.0

Answer

PSV ratio >1.5

Answer

PSV ratio >1.0

Answer

PSV ratio >3.5

Question 2

On duplex surveillance of a PTFE above-knee femoropopliteal bypass graft, a focal PSV of 380 cm/s with a PSV ratio of 3.8 is found. What is the most appropriate next step?

Accepted Answer

Refer for angiography or intervention

Answer

Repeat surveillance in 3 months

Answer

Start anticoagulation and recheck in 1 month

Answer

Document as normal variant for PTFE grafts

Question 3

A vein graft exhibiting low-velocity, monophasic waveforms throughout its length without a focal stenosis most likely represents which condition?

Accepted Answer

Impending graft failure due to inflow disease or low-flow state

Answer

Normal postoperative hemodynamics

Answer

Graft arteriovenous fistula

Answer

Successful graft remodeling

Question 4

During carotid endarterectomy surveillance, which finding at the endarterectomy site is MOST concerning for restenosis requiring intervention?

Accepted Answer

ICA PSV >300 cm/s with ICA/CCA ratio >4.0

Answer

ICA PSV of 160 cm/s with mild spectral broadening

Answer

ICA PSV of 200 cm/s with ICA/CCA ratio of 2.5

Answer

Mild intimal thickening with PSV <125 cm/s

Question 5

A patient presents 2 years after renal artery stent placement. Duplex shows an intrarenal acceleration time of 0.09 seconds with a tardus-parvus waveform. What does this suggest?

Accepted Answer

Significant in-stent restenosis proximal to the sampling site

Answer

Normal post-stent hemodynamics

Answer

Renal vein thrombosis

Answer

Acute tubular necrosis

Question 6

After endovascular aneurysm repair (EVAR), a type II endoleak is identified. What is its hemodynamic source?

Accepted Answer

Retrograde flow from patent lumbar or inferior mesenteric arteries

Answer

Inadequate proximal seal at the aortic neck

Answer

Inadequate distal seal at the iliac landing zone

Answer

Graft fabric porosity

Question 7

Which duplex finding best distinguishes a pseudoaneurysm from a perigraft hematoma at a femoral access site?

Accepted Answer

To-and-fro flow pattern ('yin-yang' sign) on color Doppler

Answer

Absence of internal color flow

Answer

Hyperechoic collection adjacent to the artery

Answer

Calcification at the margin of the collection