Abdominal Aortic Aneurysms

Abdominal aortic aneurysms (AAA) are a major cause of morbidity and mortality. Rupture of an AAA is a catastrophic event that leads to death in 80–90% of patients overall, including 50–70% of patients that reach medical attention. AAA can be described by their location and/or morphologic features. The pathophysiology is driven by abnormalities in the connective tissue of the aortic wall, namely elastin. While abnormalities in elastin lead to aneurysm formation, disruption of collagen in the aortic wall is what ultimately leads to rupture. Major risk factors for this entity include smoking, advanced age, male gender, and family history. There are a variety of modalities that are used to image abdominal aortic aneurysms. Most commonly, ultrasound is used and is recommended by several societies for screening patients at risk of this disease. While behavioral modifications are recommended in patients with AAA to improve overall cardiac health, the mainstay of management is aneurysm repair. Generally, repair of an AAA is considered once it is ≥5.0 cm. Current options for intervention include open surgical repair and endovascular aneurysm repair (EVAR). Large randomized trials to date thus far suggest that while EVAR has improved perioperative mortality, long-term mortality outcomes appear to be better in patients that undergo surgical repair. Surveillance imaging with CT is recommended in patients that undergo open surgical repair of an AAA to assess for paranastomotic aneurysm formation, while CT or ultrasound surveillance is performed in patient post-EVAR to assess for endoleak formation.