Background Elective endovascular aneurysm repair (EVAR) for abdominal aortic aneurysm has an initial survival advantage over open repair (OR), but more frequent complications increase costs and long-term aneurysm-related mortality. Randomised controlled trials of EVAR versus OR have shown EVAR is not cost-effective over a patient’s lifetime. However, in the EVAR-1 trial, post-operative surveillance may have been sub-optimal, as the importance of sac growth as a predictor of graft failure was overlooked.

Methods Real-world data informed a discrete event simulation model of post-operative outcomes following EVAR. Outcomes observed EVAR-1 were compared with those from five alternative post-operative surveillance and re-intervention strategies. Key events, quality-adjusted life years and costs were predicted. The impact of using complication and rupture rates from more recent devices, imaging and re-intervention methods was also explored.

Results Compared with observed EVAR-1 outcomes, modelling full adherence to the EVAR-1 scan protocol reduced AAA deaths by 3% and increased elective re-interventions by 44%. European Society re-intervention guidelines provided the most clinically effective strategy, with an 8% reduction in AAA deaths, but a 52% increase in elective re-interventions. The cheapest and most cost-effective strategy used lifetime annual ultrasound in primary care with confirmatory CT if necessary, and reduced AAA-related deaths by 5%. Using contemporary rates for complications and rupture did not alter these conclusions.

Conclusions All alternative strategies improved clinical benefits compared with the EVAR-1 trial. Further work is needed regarding the cost and accuracy of primary care ultrasound, and the potential impact of these strategies in the comparison with OR.