Endovascular treatment for elimination of an abdominal aortic aneurysm (AAA) can be applied if sufficient contact surface (apposition) between the endoprosthesis and the aortic wall can be achieved (proximal sealing zone). An AAA distal to the renal arteries can be treated with endovascular aortic repair (EVAR). An AAA involving branching arteries from the aorta can be treated with fenestrated EVAR (FEVAR). During FEVAR, a personalized endoprosthesis with openings (fenestrations) is used in which balloon-expandable covered stents (BECS) are placed to provide blood flow to the branching arteries. EVAR and FEVAR are associated with lower 30-day mortality than open surgical repair, but the reintervention rate is higher after endovascular repair compared to open surgical repair. After endovascular treatment, patients undergo lifelong monitoring with imaging to detect complications. The most common indication for reintervention after EVAR is type 1a endoleak caused by failure of the proximal sealing zone. The most frequent indications for reintervention after FEVAR are BECS related endoleaks, renal or visceral artery occlusion and stenosis. Determination of the proximal sealing zone and geometric analysis of BECS on standard CTA scans using CTA applied software is a valuable tool after endovascular treatment. Parameters such as the length of the proximal sealing zone and the effective oversizing of the endoprosthesis in the aortic neck provide information about the success of the endovascular treatment and further monitoring of the patient. The ability to assess the 3D geometry of a BECS-related complication contributes to targeted reintervention