Australia & New Zealand Society of Vascular Surgeons

After an endograft has been placed for treatment of AAA, followup imaging is routinely performed at intervals ranging from 6 weeks to 12 months. CT angiography and doppler Ultrasound are the two most widely available modalities for this purpose. Once an endoleak is detected its type and significance must be determined. Early in followup type II endoleaks are common and may resolve spontaneously. Other types may require urgent repeat intervention. Arterial phase CT is the primary screening modality I use. It provides accurate measurements of aneurysm diameter and is sensitive in demonstrating small volumes of flowing blood in the aneurysm sac. Direct or indirect evidence of the type and site of endoleak is usually present and becomes more obvious when images are reviewed as soft copy. Plain x-ray images and doppler ultrasound may provide additional information not present on CT. Endoleaks considered significant on screening tests are usually investigated further. DSA is the most useful modality to confirm the type and site of endoleak and to guide further treatment. Additional angiographic strategies may be required when endoleaks remain difficult to characterise.