Remodeling of aortic aneurysm and aortic neck on follow-up after endovascular repair with suprarenal fixation

Abstract

The objective of this study was to evaluate the remodeling of abdominal aortic aneurysms after endovascular aortic aneurysm repair (EVAR) with the Zenith (Cook Medical, Bloomington, Ind) device. This was a retrospective study of anatomic data related to characteristics of the aortic neck diameter, iliac artery diameter, and aneurysm sac diameter collected during a clinical study of the Zenith device. In this study, 739 patients were observed for 2 years and 158 of them were observed for 5 years. The monthly rate of change for the neck diameter was more rapid in the early postoperative period (postoperative-30 days), with an expansion of 0.7 ± 0.09 mm/month, and during the third year of follow-up (24-36 months), with a monthly expansion rate of 0.10 ± 0.24 mm. The iliac arteries were also more prone to expansion during the first postoperative month (right iliac, 0.95 ± 0.08 mm/month; left iliac, 0.91 ± 0.08 mm/month) and in the next 6 months with a monthly expansion rate of 0.18 ± 0.02 mm and 0.21 ± 0.02 mm for the right and left iliac arteries, respectively. Remodeling of the aneurysm sac occurred mainly in the first postoperative year with a regression rate of 0.89 ± 0.05 mm/month between 1 and 6 months and 0.44 ± 0.04 mm/month for the second half of the year. The aneurysm sac regression rate dropped to 0.2 mm/month in the second postoperative year. Changes in the aortic neck diameter were statistically significant (P < .001) only at the 24- to 36-month postoperative interval. Changes in the aortic sac diameter were statistically significant (P < .001) at the 30-day to 6-month, 6- to 12-month, and 12- to 24-month intervals. Among patients who underwent reintervention, aortic sac expansion occurred primarily in the 24- to 36-month interval. Expansion of the aortic neck after EVAR for the Zenith endograft occurs mainly between 24 and 36 months; aortic aneurysm sac regression occurs more obviously at 1 to 12 months. Iliac arteries at the landing zone expand more rapidly in the first postoperative year. Late surveillance of EVAR patients is essential to avoid late complications after aortic remodeling.