Beyond a certain threshold diameter, Abdominal aortic aneurysms (AAA) are treated by open surgical repair or, more often by endovascular aortic aneurysm repair (EVAR). The latter involves implantation of a stent-graft and thereby exclusion of the AAA from the blood circuit. Small vessels supplying parts of the bowel or the spine are regularly covered. In a quarter of patients, this may result in an inversion of blood flow in the mentioned vessels, leading to persistent blood flow within the AAA, referred to as type II endoleak (T2EL). Occurrence of T2EL is associated with complications like AAA growth or even rupture. Secondary interventions to treat T2EL often fail and may be highly invasive. Various risk factors for T2EL have been described. This enables prediction whether a patient is at high risk for T2EL after EVAR. Deployment of metal coils in the aneurysm sac as part of the EVAR procedure can reduce the risk for T2EL.The present study aims to assess the efficacy of sac embolization during EVAR to prevent T2EL.