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

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).

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.

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).

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.