Length measurements of the aorta after endovascular abdominal aortic aneurysm repair

Background: successful endovascular repair of abdominal aortic aneurysms (A AA) generally leads to a decrease in aneurysm size. Theoretically! this may lead to foreshortening of the excluded segment. If so, vertically rigid en dografts may dislocate over time and cover venal or hypogastric arteries. Aim: to assess length changes of the infrarenal aorta after endovascular AA A exclusion. Patients and methods: forty-four consecutive patients were scheduled for th e EndoVascular Technologies(R) endograft, a vertically non-rigid prosthesis which would potentially accommodate longitudinal changes. Twenty-four pati ents had completed at least 6 months of follow-mp. In 18/24 patients a decr ease in size was established by aneurysm volume measurements at 6 months fo llow-up. Helical computer tomography (CT) angiograms were processed on a wo rkstation. Aortic lengths were measured along the central lumen line from t he lower renal artery orifice to the native aortic bifurcation. The compute r tomography angiogram (CTA) reconstruction thickness of 2 mm yields at lea st a 4-mm error for each length measurement. Results: in the shrinking aneurysm group, the median length change was 0 mm (range -9 mm to +4 mm) at 6 months' follow-up (n = 18) and also 0 mm (rang e - 7 mm to +4 mm) at 12 months' follow-up (n = 10). In 16/18 patients, len gth changes remained within the measurement error range of 4 mm. Conclusion : in tills group of shrinking aneurysms after endovascular AAA repair, fore shortening of the excluded aortic segment appears not to be a clinically si gnificant problem.