How are endoleaks detected on post-EVAR duplex imaging?

• A. Flow within the aneurysm sac on color Doppler and careful assessment of sac size; endoleak type classification typically requires cross-sectional imaging.
• B. Endoleaks cannot be detected with duplex imaging.
• C. Only CT angiography can detect endoleaks.
• D. Detect endoleaks by measuring limb pressures.

Answer: (A)

Duplex imaging detects endoleaks by looking for blood flow inside the aneurysm sac after EVAR. On color Doppler, flow that fills the sac indicates a leak, and tracking sac diameter over time helps—persistent or enlarging sac size supports the presence of an endoleak. However, while duplex can raise suspicion and monitor changes, it cannot reliably classify the leak type or pinpoint its source. That detailed classification typically requires cross-sectional imaging such as CT angiography or MR angiography, which visualize the relation of the flow to the graft and branch vessels.