Multi-detector CT angiographic imaging in the follow-up of patients after endovascular abdominal aortic aneurysm repair (EVAR)

Abstract

BackgroundMultidetector computed tomography (MDCT) angiography represents the standard of reference in the follow-up of patients after endovascular abdominal aortic aneurysm repair (EVAR), being effective in the detection of the full spectrum of possible complications on both axial and 3D images.MethodsThe purpose of this article is to review the normal CT angiography findings of the different types of stent-grafts and to describe the radiological findings of early and late complications after EVAR on axial and reconstructed images. A selection of cases of post-EVAR MDCT angiography is presented to learn the techniques most commonly used for endovascular treatment, the correct CT scanning technique to acquire the data, the full gamut of possible procedure-related complications and how these complications usually appear on CT images.ConclusionMDCT angiography is an effective and specific technique in both the pre- and postoperative settings of EVAR procedures. A better understanding of the procedure, the devices, the normal postoperative imaging features and the possible procedure-related complications ensures optimal planning and follow-up of patients undergoing an EVAR procedure.

Usefulness of triphasic CT aortic angiography in acute and surveillance: Our experience in the assessment of acute aortic dissection and endoleak

“…Many patients require reintervention during the middle and long-term follow-up because of procedurerelated complications [38]. For this reason, surveillance of these patients is crucial to determine the long-term performance of these devices [9]. Commonly employed CT surveillance protocols recommend regular scans at 1, 6 and 12 months post-implantation and at yearly intervals thereafter.…”

“…6) [25e27]. EL is a common procedural failure due to persistent flow outside the graft within the aneurysm sac causing further enlargement and rupture of the aneurysm sac itself [9,28,29]. CT protocol considered most reliable in detecting complications consists of a triphasic protocol including unenhanced, arterial phase (30-s delay), and delayed (120-to 300-s delay) phases, and it has been preferred for post-EVAR surveillance [8,9,25].…”

“…EL is a common procedural failure due to persistent flow outside the graft within the aneurysm sac causing further enlargement and rupture of the aneurysm sac itself [9,28,29]. CT protocol considered most reliable in detecting complications consists of a triphasic protocol including unenhanced, arterial phase (30-s delay), and delayed (120-to 300-s delay) phases, and it has been preferred for post-EVAR surveillance [8,9,25]. The unenhanced images can be helpful to avoid false-positive diagnoses, distinguishing hyperdense materials from an EL that appears on the arterial and/or delayed phase, but generally absent on image [8,9,25].…”

“…CT protocol considered most reliable in detecting complications consists of a triphasic protocol including unenhanced, arterial phase (30-s delay), and delayed (120-to 300-s delay) phases, and it has been preferred for post-EVAR surveillance [8,9,25]. The unenhanced images can be helpful to avoid false-positive diagnoses, distinguishing hyperdense materials from an EL that appears on the arterial and/or delayed phase, but generally absent on image [8,9,25]. Then, unenhanced phase enables differentiation between true ELs and areas of calcification or high attenuation that mimic ELs (pseudo-ELs) [8,9,25].…”

“…The unenhanced images can be helpful to avoid false-positive diagnoses, distinguishing hyperdense materials from an EL that appears on the arterial and/or delayed phase, but generally absent on image [8,9,25]. Then, unenhanced phase enables differentiation between true ELs and areas of calcification or high attenuation that mimic ELs (pseudo-ELs) [8,9,25]. Because ELs have variable flow rates, they can be detected at variable times after CM administration.…”