Snapshot A 61-year-old man presents to the emergency department for vague abdominal and back pain. He says that his symptoms progressively worsened over the course of months and cannot identify an initiating cause. Medical history is significant for hypertension. He has been smoking 1 pack of cigarettes per day for the past 30 years. On physical exam, the patient has an enlarged pulsatile mass of approximately 5 cm in diameter. Introduction Clinical definition a segmental and full thickness dilation of the abdominal aorta Epidemiology risk factors for AAA age male gender tobacco smoking family history Caucasian race atherosclerosis Pathogenesis pathoanatomy the abdominal aorta is a retroperitoneal structure that begins in the hiatus of the diaphragm bifurcates into the right and left iliac common arteries these arteries can also become aneurysmal an aneurysm typically develops below the renal arteries and above the common iliac arteries pathophysiology elastin fibers become disrupted and collagen becomes degraded, resulting in a loss of elasticity in the aortic wall Prognosis risk of rupture depends primarily on size (AAA with diameter >5.5 cm are at highest risk) Presentation Symptoms/physical exam asymptomatic (the majority of cases) an enlarged abdominal mass and an abdominal bruit may be found in symptomatic but not ruptured cases abdominal, back, or flank pain in symptomatic and ruptured cases severe pain, hypotension, and a pulsatile mass Imaging Abdominal ultrasound to screen for asymptomatic AAA in high-risk patients Abdominal CT (contrast-enhanced) for symptomatic patients who are hemodynamically stable Treatment Operative abdominal aortic aneurysm (AAA) repair indication ruptured AAA symptomatic, unruptured AAA asymptomatic large AAA (>5.5 cm diameter) Complications Rupture