Use of Contrast-Enhanced Ultrasound in Follow-up of Endovascular Aneurysm Repair

The optimal protocol for imaging and timing of endovascular aortic aneurysm repair (EVAR) follow-up is still being developed. Various follow-up modalities are employed to measure aortic sac diameter, to detect and classify endoleaks, to detect morphologic details of the stent-graft (e.g., graft occlusion), and to detect imaging evidence of endograft infection and other details. A recent systematic review reported that more than 90% of EVAR patients undergoing follow-up do not benefit from surveillance, since imaging alone initiates asymptomatic secondary interventions (SIR) in only 1.4% to 9% of patients. Therefore the least invasive and safest EVAR follow-up protocol is needed so that radiation-induced and other complications from surveillance imaging do not exceed the risk of complications from EVAR itself. The “Achilles’ heel” of EVAR is the presence of endoleak and the indication/timing for SIR, especially for type II endoleaks, the most commonly encountered variety. This chapter examines the role of contrast-enhanced ultrasound (CEUS) in the follow-up of patients after EVAR.