Postoperative imaging after endovascular AAA repair.

Unlike open aortic aneurysm repair, follow-up is vital for endovascular aneurysm repair. If there is no perigraft flow or endoleak after endograft placement, the natural history is a decrease in aneurysm size. However, a significant number of aneurysms after endograft repair enlarge without apparent endoleak, and ruptures have occurred in this situation. Aneurysms so treated also can develop a late, secondary endoleak that leads to rupture. Late stent deformation has been noted in abdominal and thoracic applications, and deformation can ultimately lead to graft thrombosis, endoleak, and aneurysm rupture. For these reasons, regular postoperative imaging will likely be needed for the life of the patient after endovascular aortic aneurysm repair, and it must be capable of accurately detecting endoleak, aneurysm expansion, graft migration, and graft deformation. As with the entire field of endovascular surgery, imaging techniques and recommendations regarding their use are changing rapidly. However, a combination of examinations appears superior to any single test. Only long-term follow-up data can determine which methods will become standard, but physical examination, abdominal radiographs, and spiral computed tomography (CT) with specialized 3D reconstruction protocols are the current gold standard. In centers of excellence, color or power Doppler ultrasound is a useful adjunctive study and ultimately may decrease the required frequency of more expensive studies such as CT with specialized protocols.