Evolution and clinical relevance of common iliac artery seal zone after endovascular aortic aneurysm repair

Objective

Data in literature suggest iliac artery dilatation and endograft retraction as complications after endovascular aneurysm repair. However, mainly older generation endografts were included. Therefore, we sought to evaluate the distal sealing zone chronological changes after endovascular aneurysm repair with newer generation stent-grafts.

Methods

Clinical and radiological data of patients with abdominal aortic aneurysms treated with endovascular aneurysm repair between January 2010 and December 2013 were reviewed. Measurements were made using volumetric reconstructions in the first and last available computed tomography angiography. Endpoints of the study were the presence of iliac dilatation and retraction of the endograft. Association with distal oversizing and sealing length was analyzed.

Results

Consecutive patients with a total of 52 common iliac arteries were included in the study (mean age 74.9 ± 6.8 years, four women (7.7%)). The mean follow-up was 3.1 years. The mean iliac diameter increased from 15.5 to 17.1 mm ( p < .001) in the first control computed tomography angiography and to 18.7 mm ( p < .001) in the last available computed tomography angiography. No endograft (Endurant by Medtronic (24/52; 46%), Excluder de Gore (23/52; 44%), Zenith by Cook (5/52; 9%)) was associated with dilatation ( p = .066) or iliac retraction ( p = .591). Two type Ib endoleaks were found (3.8%) and successfully treated with distal graft extension. An iliac branch retraction of ≥5 mm was identified in seven cases (13%). Iliac arteries treated with limbs of ≥24 mm in diameter dilated significantly more than the rest of limbs (5.37 mm versus 3.12 mm; p = .022). In the last available imaging, iliac dilatation was ≥20% in 28 cases (53.8%) and had exceeded the diameter of the implanted endograft in 20 cases (38.4%). Iliac dilatation (OR 15.11 per mm, p = .025) was identified as a risk factor for retraction ≥5 mm.

Conclusion

Iliac dilatation and endograft limb retraction are common findings after endovascular aneurysm repair despite the use of new generation endografts. Optimizing the iliac sealing length and meticulous computed tomography angiography surveillance are recommended especially in case of use ≥24 mm iliac stent-grafts to prevent possible complications.