ABSTRACT
BACKGROUND: Endovascular aortic repair (EVAR) has become the preferred treatment for abdominal aortic aneurysm (AAA). Its main aim is to seal the perfusion of the aneurysmal sac and, thus, induce sac regression and subsequent aortic remodelling. Aneurysmal sac regression has been linked to the short- and long-term clinical outcomes post-EVAR. It has also been shown to be influenced by endograft device choice, with several of these available commercially. This review summarises and discusses current evidence on the influence of pre- and intraoperative factors on sac regression. Additionally, this review aims to highlight the device-specific variations in sac regression to provide an overall holistic approach to treating AAAs with EVAR. METHODS: A comprehensive literature search was conducted using multiple electronic databases to identify and extract relevant data. RESULTS: Female sex, >70 mm original sac diameters, higher pre-procedural fibrinogen levels, smoking and low intra-aneurysmal pressure were found to positively impact sac regression. Whereas renal impairment, ischemic heart disease, high intra-aneurysmal pressure and aneurysm neck thrombus negatively influenced sac regression. Patent lumbar arteries, age, statins and hypercholesterolaemia displayed conflicting evidence regarding sac regression. Regarding the EVAR endografts compared, newer generation devices such as the Anaconda mainly showed the most optimal results. CONCLUSION: Sac regression following EVAR in AAA is an important prognostic factor for morbidity and mortality. Nevertheless, several pre- and intraoperative factors can have an influence on sac regression. Therefore, it is necessary to take them into account when assessing AAA patients for EVAR to optimise outcomes. The choice of EVAR stent-graft can also affect sac regression, with evidence suggesting that the Fenestrated Anaconda is associated with the most favourable results.