Case of the month - August
Contrast-enhanced tomographic ultrasound for endoleak detection and classification following endovascular aneurysm repair: case study
Adriano José de Souza, Director Ecocenter Medicina Diagnóstica, Belo Horizonte, Brazil
An endoleak is defined as persistent blood flow in the aneurysm sac following stent grafting. Endoleaks may cause pressurization of the aneurysm sac and can lead to aneurysm rupture after endovascular aneurysm repair (EVAR). Contrast-enhanced computed tomography (CTA) is considered the gold standard for the detection and classification of endoleaks. Nevertheless, cumulative radiation dose, cost, and increased demand for computed tomography aortography suggest that duplex ultrasonography (DU) may be an alternative to CTA-based surveillance after EVAR. Contrast-enhanced ultrasound (CEUS) involves the intravenous administration of a stable suspension of sulfur hexafluoride micro-bubbles surrounded by a phospholipid shell as an ultrasound contrast agent enhancing the visualization of flowing blood. Although CEUS was first reported 19 years ago, studies demonstrating an improved sensitivity for endoleak to at least the level equivalent to CTA, have only recently been performed. Contrast-enhanced tomographic ultrasound (CEtUS) uses a magnetic position tracking system to convert a sequence of 2D ultrasound images into a 3D volume. It enables visualization of DU images in three dimensions with ultrasound contrast highlighting blood flow of endoleaks. It allows multiplanar reconstructions and image manipulation in any 3D plane. The case presented highlights the added benefit of CEtUS in endoleak detection and classification after EVAR.