Large diameter (≥29 mm) proximal aortic necks are associated with increased complication rates after endovascular repair for abdominal aortic aneurysm.

AIM: To investigate the impact of proximal aortic diameter on outcome after endovascular repair (EVAR) of infrarenal abdominal aortic aneurysms.

METHODS: This was a case-control (1:1) retrospective analysis of prospectively collected data on 732 AAA patients treated with EVAR in two university centers. Patients with an infra-renal 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 aneurismal sac diameter. Any patients treated outside the instructions for use of each endograft or with not 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: 64 patients with a proximal neck diameter of 29-32mm (WN group) were compared with a matched control group of 64 patients with a neck diameter of 26-28.9mm (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 months), (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 endpoint at 36 months (SE <10%) was 87.3% for the study vs. 98.4% for the control group (log rank=4.66, p=0.03). On multiple regression analysis, the presence of a proximal aortic neck >29mm was the only independent risk factor for neck related adverse events (OR 7.4; 95% CI 1.2-47.1).

CONCLUSION: 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.