Chapter 56: Endovascular Therapies for Abdominal Aortic Aneurysm

INTRODUCTION

Rupture of abdominal aortic aneurysms (AAAs) accounts for over 15,000 deaths per year in the United States and is the 10th leading cause of death in men older than 55 years of age (Fig. 56-1).¹ Out-of-hospital AAA rupture is associated with a mortality of 80% to 90%. Most deaths are preventable by the early diagnosis and treatment of AAA, and as a result, more than 60,000 surgical or endovascular procedures for AAA are performed annually in the United States. Despite the excellent results of open surgical repair for the prevention of aneurysm rupture, this procedure is associated with significant morbidity and mortality, especially in high-risk patients. Endovascular aneurysm repair (EVAR), which was developed as a less invasive alternative to open surgical repair, is gaining widespread acceptance and is now performed in approximately 80% of elective aneurysm repairs. This chapter reviews the epidemiology, technical aspects, outcomes, and complications of EVAR for the treatment asymptomatic and symptomatic AAA.

EPIDEMIOLOGY AND NATURAL HISTORY OF ABDOMINAL AORTIC ANEURYSM

The incidence of AAA increases with age. Approximately 2.6% of men and 0.5% of women between 45 and 54 years of age have an AAA, and by 75 to 84 years of age, 19.8% of men and 5.2% of women have an AAA.¹ Men are affected 4 to 6 times more frequently than women.² AAA is also more common in Caucasian patients than in black, Hispanic, or Asian patients.³

Approximately 15% of patients with AAA have a family history of AAA.⁴ Because the pathogenesis of AAA is thought to be multifactorial, including disorders of enzymes regulating connective tissue homeostasis, approximately 5% of patients with an AAA have a concomitant thoracic aneurysm and approximately 15% have either a femoral artery aneurysm or a popliteal aneurysm.⁵ Synchronous peripheral aneurysms are more common in men, while synchronous thoracic aneurysms may be more common in women.⁶ Approximately 10% of AAAs are juxtarenal, and iliac artery involvement occurs in up to 22% of AAAs.

Patients with AAAs often have significant medical and cardiac comorbidities. Coronary artery disease is found in 40% to 70% of patients with AAAs, with evidence of prior myocardial infarction in up to 46% of patients.⁷ Cerebrovascular disease is present in 25% of patients, claudication is present in 28%,⁷ hypertension is present in 55%, and chronic obstructive lung disease is present in approximately 20% to 25%. A history of blunt abdominal trauma is occasionally found; this can lead to both true aneurysms and pseudoaneurysms of the abdominal aorta. Most studies have shown that AAAs are approximately 6 to 7 times more common in smokers, whereas elevated high-density lipoprotein cholesterol (HDL-C) may ...