Post-Intervention and Grafts Flashcards

After ultrasound-guided thrombin injection for pseudoaneurysm treatment, which finding confirms successful occlusion?

Answer: Complete absence of flow within the pseudoaneurysm sac on color and spectral Doppler

Successful thrombin injection is confirmed by the complete absence of Doppler-detectable flow within the entire pseudoaneurysm sac immediately after injection.

During graft surveillance, an elevated velocity is found only at the distal anastomosis. B-mode imaging shows intimal hyperplasia at the toe of the anastomosis. What is the expected long-term natural history if untreated?

Answer: Progressive stenosis likely leading to graft thrombosis within months to years

Distal anastomotic intimal hyperplasia is a progressive lesion that, if left untreated, typically leads to high-grade stenosis and eventual graft thrombosis.

On duplex evaluation after iliac artery stenting, which finding is MOST suggestive of in-stent restenosis rather than external compression?

Answer: Focal PSV elevation within the stent with normal velocities immediately proximal and distal

In-stent restenosis produces focal velocity elevation confined to the intraluminal stenosis, with velocity normalization proximal and distal to the lesion.

A patient with a reversed saphenous vein graft undergoes duplex 2 years postoperatively. A valve cusp remnant is identified causing turbulent flow with a PSV ratio of 1.8. What is the recommended management?

Answer: Close interval surveillance (every 3 months) to monitor for progression, with referral if ratio exceeds 2.0

A PSV ratio of 1.8 at a valve site does not yet meet the >2.0 threshold for intervention but warrants shortened surveillance intervals to detect progression.

When evaluating a composite sequential bypass graft (vein proximally, PTFE distally with distal vein cuff), where is the HIGHEST risk location for stenosis development?

Answer: The vein-to-PTFE anastomosis and the distal vein cuff-to-native artery anastomosis

Composite graft failure is most common at the synthetic-to-vein junction and the distal anastomosis where intimal hyperplasia preferentially develops at material transitions and anastomotic sites.

After carotid artery stenting, a patient is found to have a PSV of 340 cm/s within the stent at a 12-month follow-up. The most appropriate classification and action is:

Answer: Severe in-stent restenosis (>70%); refer for catheter angiography to consider re-intervention

ICA PSV >300 cm/s within a carotid stent meets the duplex threshold for severe restenosis (>70%), requiring angiographic confirmation and consideration of re-intervention.

Which arteriovenous fistula (AVF) feature on duplex is associated with the HIGHEST risk of access failure within 6 months?

Answer: Juxta-anastomotic stenosis with PSV ratio >3.0 and access flow <500 mL/min

Juxta-anastomotic stenosis causing a PSV ratio >3.0 combined with reduced access flow below 500 mL/min predicts imminent AVF failure and requires urgent intervention.