Plain radiographic surveillance of abdominal aortic stent-grafts: the Liverpool/Perth protocol.
To present a protocol for plain radiographic surveillance of abdominal aortic stent-grafts that addresses the main variables in need of standardization: (1) patient position, (2) radiographic centering point, and (3) focus-to-film distance. Our policy is to perform baseline anteroposterior and lateral films following endoluminal grafting and repeat the studies annually. These are the most important films to assess migration and component separation; supplementary right and left posterior oblique radiographs may help identify wireform fractures. It is best to perform radiography before computed tomography if both tests are scheduled for the same day, as excretion of intravenous contrast opacifies the renal collecting systems and interferes with radiographic analysis. Evaluation of the radiographs depends on the design of the stent-graft, so it is important to understand graft construction and the position of the radiopaque markers to best assess changes on follow-up films.