Introduction:The continued high incidence of adverse clinical outcomes following endovascular aneurysm repair (EVAR) of abdominal aortic aneurysm (AAA) has created the need to predict these outcomes in order to aid patient management. This study sought to explore the potential role of some pre-surgical anatomic aneurysm features in predicting adverse clinical outcomes post EVAR.Methods: This was a retrospective cohort study that utilized the data of 661 patients from the United Kingdom (UK) EVAR 1 and 2 randomised controlled trials. The aneurysm anatomic features that served as predictors were aortic neck and sac length (NSL), proximal aortic neck diameter (PAND), and distal aortic neck diameter (DAND). The primary outcomes of interest were all-cause mortality and AAA-related mortality, while the secondary outcomes of interest were graft-related complications and reinterventions. Survival analysis using Cox proportional hazard regression models was utilized to estimate the associations between the exposure variables and outcomes of interest using R software.Results: The median age of the participants was 75 years (IQR 70-79 years) with the majority being males (90%). The total follow-up duration of participants in the study was 4,733 person-years with a median follow-up duration of 7.3 years . The overall survival rates were 74.4%, 63.5%, and 34.6% at three, five, and 10 years, respectively. NSL was significantly associated with graft-related complications and reintervention. Every 1cm increase in NSL yielded a 7% and 73% increase in the rate of graft-related complication and intervention, respectively (P<0.1). The rate of reintervention also increased by 13% for every 1cm increase in DAND. These anatomic features variables were, however, not observed to be predictive of all-cause death and AAA-related death.
Conclusion:Increasing NSL and DAND are potential aneurysm anatomic features that could be used to predict post-EVAR adverse outcomes, though further research to validate these results is needed.