Endologix Stent-graft

Arterial phase CT shows smoothly marginated contrast extending beyond the confines of the metal struts of the stent

Delayed CT shows the smoothly marginated contrast extending beyond the confines of the metal strut unchanged in size and configuration when compared to arterial phase imaging

Most endostent devices used for endovascular repair of aortic aneurysms have the graft material sutured on the luminal side of the stent. The AFX endostent device (Endologix, Irvine, California) is different from other devices in that the graft material is sutured on the outside of the metal component, attached only at the proximal and distal ends.

By intent, the graft material of the AFX stent-graft can separate from the metal struts where it is not directly apposed to the aortic wall.  During surveillance with contrast-enhanced imaging of patients who have reviewed this device, contrast can be detected outside of the metallic construct. Although this finding can imply a type 1 or 3 endoleak when identified with other endostents, it is a normal finding with the AFX device.

Avoiding misinterpretation as an endoleak can be achieved by confirmation of the type of endostent device used for aneurysm repair. In addition, the contrast extending beyond the metal struts does not change in configuration or size on delayed imaging.

References:

J Vasc Interv Radiol. 2012 Nov;23(11):1544-6.