Which imaging modality is most commonly used to surveil EVAR for endoleaks?

• A. Duplex ultrasound
• B. Magnetic resonance angiography
• C. CT angiography
• D. Conventional angiography

Answer: (C)

After EVAR, the goal of surveillance is to reliably detect endoleaks, monitor aneurysm sac size, and assess the graft for any issues. CT angiography is the most commonly used modality because it provides fast, high-resolution, contrast-enhanced images that clearly show blood flow around the graft, pinpoint the exact location of any leak, and simultaneously measure sac expansion and evaluate graft components in one study. This combination makes CT angiography highly sensitive and practical for routine follow-up across all endoleak types. Other methods have roles but come with limitations: duplex ultrasound is highly operator-dependent and can miss leaks or be limited by patient habitus; magnetic resonance angiography avoids radiation but carries concerns about gadolinium in renal disease and can be degraded by metal artifacts from the graft; conventional angiography is invasive and reserved for cases where endoleaks are suspected and an intervention is planned. Thus, CT angiography remains the standard for EVAR surveillance due to its comprehensive, noninvasive, and widely available assessment.