Multicentre Post-EVAR Surveillance Evaluation Study (EVAR-SCREEN)

Abstract

Objective: Surveillance imaging is considered mandatory after endovascular aneurysm repair (EVAR), but many patients are lost to follow up and the impact of this is poorly understood. This study aimed to examine compliance with post-operative surveillance in the UK and the impact of mal-/non-compliance on endograft re-interventions and survival.

Methods: EVAR-SCREEN centres reported EVAR for intact infrarenal abdominal aortic aneurysms (AAA) from 1 January 2007 to 31 December 2010, with follow up included up to 31 July 2014. Non-compliance was defined by the presence of a single 18 month period in which no surveillance imaging was performed. The outcomes were reported in compliant and non-compliant groups with survival analysis.

Results: EVAR was performed in 1414 patients in 10 UK centres. At the end of the study period there were 378 patients with five years of follow up available for analysis. Compliance with surveillance was 66% (61-68%). Compliance varied widely, from 9% to 88% between centres. Age (hazard ratio [HR] 1.03, 95% confidence interval [CI] 1.01-1.05; p = .02) and distance from hospital (HR 1.01, 95% CI 1.00-1.01; p < .001) were independent predictors of non-compliance. Non-compliant patients had lower all cause mortality in the first three years after EVAR, whereas compliant patients had lower all cause mortality 4-5 years after EVAR (p < .001). No significant difference in re-intervention rates was found between compliant and non-compliant patients.

Conclusion: A substantial proportion of patients were non-compliant with surveillance after EVAR in the UK with considerable variation between centres. The survival benefit for EVAR after three years appeared to be related to compliance with surveillance which has implications for the future delivery of EVAR.

Keywords: Abdominal aortic aneurysm; Endovascular procedures; Epidemiology; Stents.