International trends in patient selection for elective endovascular aneurysm repair: sicker patients with safer anatomy leading to improved 1-year survival

Background: To review the trends in patient selection and early death rate for patients undergoing elective endovascular repair of infrarenal abdominal aortic aneurysms (EVAR) in 3 countries. For this study, audit data from 4,163 patients who had undergone elective infrarenal EVAR were amalgamated. The data originated from Australia, Canada (Ontario), and England (London, Cambridge, and Leicester). Methods: Statistical analyses were undertaken to determine whether patient characteristics and early death rate varied between and within study groups and over time. The study design was retrospective analysis of data collected prospectively between 1999 and 2012. Results: One-year survival improved over time ( P = 0.0013). Canadian patients were sicker than those in Australia or England ( P < 0.001). American Society of Anesthesiologists classification (ASA) increased over time across all countries although more significantly in Canada. Age at operation remained constant, although older patients were treated more recently in London ( P < 0.001). English centers treated larger aneurysms compared with Australia and Canada ( P < 0.001). Australian centers treated a much larger proportion of aneurysms that were <55 mm than other countries. Preoperative creatinine levels decreased over time for all countries and centers ( P < 0.001). Infrarenal neck angles have significantly decreased over time ( P < 0.001). Recent data from London (UK) showed that operations were performed on longer ( P < 0.001) and wider ( P < 0.001) infrarenal necks than elsewhere. Conclusions: In this international comparison, several trends were noted including improved 1-year survival despite declining patient health (as measured by increasing ASA status). This may reflect greater knowledge regarding EVAR that centers from different countries have gained over the last decade and improved medical management of patients with aneurysmal disease.Robert A. Fitridge, Margaret Boult, Clare Mackillop, Tania De Loryn, Mary Barnes, Prue Cowled, Matthew M. Thompson, Peter J. Holt, Alan Karthikesalingam, Robert D. Sayers, Edward Choke, Jonathan R. Boyle, Thomas L. Forbes and Teresa V. Novic