Large Diameter (≥29 Mm) Proximal Aortic Necks Are Associated with Increased Complication Rates after Endovascular Repair for Abdominal Aortic Aneurysm

BACKGROUND:The aim of this study is to investigate the impact of proximal aortic diameter on outcome after endovascular aneurysm repair (EVAR) of infrarenal abdominal aortic aneurysms (AAAs). METHODS:This is a case-control (1:1) retrospective analysis of prospectively collected data on 732 AAA patients treated with EVAR in 2 university centers. Patients with an infrarenal neck diameter of 29-32 mm (wide neck, WN group) were compared with patients with a neck diameter of 26-28.9 mm (control group) matched for age, gender, and maximum aneurysmal sac diameter. Any patients treated outside the instructions for use of each endograft or with no adequate follow-up were excluded. The primary end point was any neck-related adverse event (a composite of type Ia endoleak, neck-related secondary intervention, and endograft migration) during follow-up. RESULTS:Sixty-four patients with a proximal neck diameter of 29-32 mm (WN group) were compared with a matched control group of 64 patients with a neck diameter of 26-28.9 mm (control group). Oversizing was significantly higher in the study group (17.9% vs. 15.5%, P = 0.001). Overall median available follow-up was 24 months (range 12-84) (WN group 24 months vs. control group 18.5 months, P = 0.943). Primary end point was recorded in 8 patients (12.5%) of the WN group and in 1 patient (1.6%) of the control group. Freedom from the primary end point at 36 months (standard error <10%) was 87.3% for the study versus 98.4% for the control group (log rank = 4.66, P = 0.03). On multiple regression analysis, the presence of a proximal aortic neck >29 mm was the only independent risk factor for neck-related adverse events (odds ratio 7.4, 95% confidence interval 1.2-47.1). CONCLUSIONS:EVAR in the presence of a wide proximal aortic neck is likely to be associated with higher adverse neck-related event rates and thus, in such cases closer follow-up may be required.