Medical Aspects of Abdominal Aortic Aneurysm

An abdominal aortic aneurysm (AAA) is defined as aortic diameter ≥30 mm measured by ultrasound. AAA prevalence increases with age and is higher in men, but has decreased during the last decades, related to lower smoking rates. Tobacco smoking, concomitant atherosclerosis, arterial hypertension, and family history are the most common risk factors. AAA has atherosclerotic, inflammatory, apoptotic, and degenerative features, and is most often asymptomatic. Aneurysm growth confers an increased risk for rupture, which can be prevented through regular follow-up of smaller AAA with ultrasound, followed by preventive surgical or endovascular interventions in selected cases. Medical therapy does not decrease the growth or rupture rate of AAA, but is indicated as mortality from cardiovascular disease in AAA patients is higher than mortality caused by AAA rupture. Treatment with statins, antihypertensive, and antiplatelet agents is associated with better five-year survival in AAA patients, and should be conducted in accordance with guidelines. Patients with AAA diameters ≥5.5 cm in men and ≥5.0 cm in women, with symptoms, or with an AAA growth rate of ≥1.0 cm/year should be evaluated by a vascular surgeon regarding operative treatment. This chapter covers aspects of diagnosis, surveillance, and medical treatment in AAA, whereas preoperative risk assessment, endovascular, and open surgical methods are described in textbooks in vascular surgery.