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

Objective: 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.

Methods: 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.

Results: 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.

Conclusions: 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.