Direct aneurysm sac catheterization and embolization of an enlarging internal iliac aneurysm using cone-beam CT

Since cone-beam computed tomography (CT) has been adapted for use with a C-arm system it has brought volumetric CT capabilities in the interventional suite. Although cone-beam CT image resolution is far inferior to that generated by traditional CT scanners, the system offers the ability to place an access needle into position under tomographic guidance and use the access to immediately begin a fluoroscopic procedure without moving the patient. We describe a case of a “jailed” enlarging internal iliac artery aneurysm secondary to abdominal aortic aneurysm repair, in which direct percutaneous puncture of the internal iliac artery aneurysm sac was performed under cone-beam CT guidance.When planning for successful abdominal endovascular aneurysm repair (EVAR), it is important to evaluate if there are associated internal iliac artery (IIA) aneurysms and the potential for type II endoleaks via retrograde IIA flow. In cases of short, ectatic, or aneurysmal common iliac arteries, placement of the distal limb of the stent graft into the external iliac artery may be necessary to ensure safe graft limb positioning and an adequate seal. In situations such as this, where there is not an associated IIA aneurysm, standard therapy is to embolize the origin of the IIA prior to stent graft placement in order to prevent type II endoleaks (1).The situation should be differentiated from the setting in which the IIA is not just a potential source of a type II endoleak, but is also aneurysmal. In this setting, embolization of the affected IIA origin is insufficient to protect the IIA aneurysm from retrograde perfusion and potential rupture (Fig. 1). This retrograde perfusion can lead to persistent aneurysm sac pressurization with subsequent aneurysm enlargement and increased risk of rupture. Furthermore, proximal embolization precludes future antegrade access into the aneurysm if an additional intervention is needed. The standard endovascular treatment of an isolated IIA aneurysm consists of embolic occlusion of all inflow and outflow branches (2). Hence, when an IIA aneurysm is associated with an abdominal aortic aneurysm (AAA), it should be treated in a similar manner prior to endograft placement (3).Open in a separate windowFigure 1.Illustration demonstrates endovascular aneurysm repair of an abdominal aortic aneurysm extending into the common iliac arteries and internal iliac arteries (IIA), with embolization of all inflow and outflow branches of the IIA to prevent enlargement of the IIA aneurysms. (Illustration by D.C. Botos)We present a case of cone-beam computed tomography (CBCT) guided direct puncture of a “jailed” enlarging IIA aneurysm. The IIA aneurysm was not directly accessible through an antegrade endovascular approach secondary to prior IIA origin coil occlusion and stent graft exclusion of the IIA orifice.