Endovascular aneurysm repair: is imaging surveillance robust, and does it influence long-term mortality?

Abstract

Endovascular aneurysm repair (EVAR) is the dominant treatment strategy for abdominal aortic aneurysms. However, as a result of uncertainty regarding long-term durability, an ongoing imaging surveillance program is required. The aim of the study was to assess EVAR surveillance in Scotland and its effect on all-cause and aneurysm-related mortality. A retrospective analysis of all EVAR procedures carried out in the four main Scottish vascular units. The primary outcome measure was the implementation of post-EVAR imaging surveillance across Scotland. Patients were identified locally and then categorized as having complete, incomplete, or no surveillance. Secondary outcome measures were all-cause mortality and aneurysm-related mortality. Cause of death was obtained from death certificates. Data were available for 569 patients from the years 2001 to 2012. All centers had data for a minimum of 5 contiguous years. Surveillance ranged from 1.66 to 4.55 years (median 3.03 years). Overall, 53 % had complete imaging surveillance, 43 % incomplete, and 4 % none. For the whole cohort, all-cause 5-year mortality was 33.5 % (95 % confidence interval 28.0-38.6) and aneurysm-related mortality was 4.5 % (.8-7.3). All-cause mortality in patients with complete, incomplete, and no imaging was 49.9 % (39.2-58.6), 19.1 % (12.6-25.2), and 47.2 % (17.7-66.2), respectively. Aneurysm-related mortality was 3.7 % (1.8-7.4), 4.4 % (2.2-8.9), and 9.5 % (2.5-33.0), respectively. All-cause mortality was significantly higher in patients with complete compared to incomplete imaging surveillance (p < 0.001). No significant differences were observed in aneurysm-related mortality (p = 0.2). Only half of EVAR patients underwent complete long-term imaging surveillance. However, incomplete imaging could not be linked to any increase in mortality. Further work is required to establish the role and deliverability of EVAR imaging surveillance.