Influence of Proximal Fixation on Aneurysm Neck Evolution after Endovascular Treatment of Infrarenal Aneurysms

Background

We analyzed the long-term influence of fixation systems on proximal aortic neck (PAN) evolution by comparing 2 late-generation endoprostheses, Endurant (Medtronic Vascular, Minneapolis, Minn) with suprarenal fixation (SRF) and Excluder (W.L Gore & Associates, Flagstaff, Ariz) with infrarenal fixation (IRF).

Methods

Our retrospective observational study included consecutive patients undergoing endovascular aneurysm repair (EVAR) for aorto-iliac aneurysms (2011–2020). Primary end points: neck enlargement and freedom from significative PAN enlargement (5 mm). Secondary end points: neck-related reintervention, endoleaks and graft migration. Results were reported following the Society of Vascular Surgery reporting standards.

Results

139 patients were included (97 in SRF group and 42 in IRF group). A difference in growth at 10 mm caudal to lowest renal artery at 2 years follow-up was found (mean growth of 1.92 ± 3.38 mm in SRF and 0.16 ± 6.86 mm in IRF; P < 0.001). A tendency to a major growth in SRF at 4 years follow-up at the lowest renal artery (1.27 ± 3.36 mm vs. 0.63 ± 2.2 mm; P = 0.06), 5 mm distal to lowest renal artery (2.17 ± 3.52 mm vs. 0.94 ± 2.76 mm; P = 0.001) and 10 mm distal to lowest renal artery (2.65 ± 3.86 mm vs. 1.12 ± 1.5 mm; P < 0.001) was shown. Freedom from PAN enlargement was 96.65% and 88.20% in SRF and 100% and 94.4% in IRF at 2 and 4 years follow-up respectively (log rank 0.041). A greater incidence of type II endoleaks in IRF was observed (40.48% vs. 15.46%; P = 0.001). Oversizing >15% showed to be a risk factor of PAN enlargement (odds ratio 6.85; 95% confident interval: 1.67–28.4; P = 0.007).

Conclusions

A small but significative percentage of patients after EVAR show a progressive PAN enlargement, being significatively greater in SRF, without increasing neck-related complications 4 years after graft deployment.