Institutional differences in endovascular aneurysm repair and aneurysm morphology

Variability exists between institutions in the application of endovascular aneurysm repair (EVAR). This study compares patient-specific variables from a high-volume North American institution with one from the UK.

One hundred consecutive patients from each institution were studied. All were treated for an intact, infrarenal aortic aneurysm. Patient characteristics and aneurysm-related variables, measured from computed tomography according to Society for Vascular Surgery (USA) reporting standards, were examined.

The median (range) age of the American patients was 74 (55-97) years and that of the British patients, 73 (49-89) years. There were 78 men in the American group and 79 men in the British group. All American patients were treated by EVAR compared to 11 % of the British group. Mean (SD) aneurysm diameter for the former was 55 (9) mm and for the latter 64 (11) mm (P < 0.001). While there was no difference in mean diameter of the infrarenal aortic neck (P = 0.918), the aneurysms of British patients (22 %) were more likely to be angulated >60° than those of the American patients (11 %) (P = 0.039). Furthermore, the mean (SD) length of infrarenal aortic neck was shorter in the British patients [21 (11) mm] compared to the American group [25 (12) mm] (P = 0.003). The mean diameter of the common iliac arteries was larger in the British patients than in the American group (P < 0.001). Mean external iliac artery diameter was no different between the groups (P = 0.507).

This group of British patients have a more advanced pattern of aneurysm morphology than American patients of similar age. This difference may, in part, explain variability in the application of EVAR.