Endovascular Repair of Abdominal and Thoracic Aortic Aneurysms

Abstract

Aortic aneurysms remain a challenging problem for patients and physicians. There have been major advances in the treatment of large-vessel aneurysms during the past 10 years. The surgical armamentarium used to treat these aneurysms now includes an endovascular approach that allows the insertion of a graft to exclude the aneurysm sac from blood flow. The endovascular repair of abdominal and thoracic aortic aneurysms has become a viable alternative to open repair and is often the approach of choice for high-risk patients. In this review, we examine the endovascular treatment of abdominal and thoracic aortic aneurysms. Abdominal aortic aneurysms (AAAs) are a formidable diagnosis for patients. This is a life-threatening condition that mandates consideration of repair. A ruptured AAA has a mortality rate approaching 90%; however, when an AAA is repaired electively, the mortality drops to less than 5%.1–3 There is, therefore, a clear advantage to treating these aneurysms before they rupture. Because this disease affects 4% to 7% of adults over the age of 65 years, with a far greater prevalence in males than females, clinicians will encounter this problem more frequently as the population ages.4 AAAs usually develop in patients with a history of arteriosclerosis or smoking. Patients present for repair when it is discovered that there is a dilation of their abdominal aorta to a diameter 1.5 times normal. The result is a weakened aortic wall that is at increased risk of rupture. The pathogenesis of this aortic wall change likely involves enzymes responsible for elastin and collagen breakdown.5 Recent research has focused on the role of metalloproteinase-9 (MMP-9). Aneurysm presence and size have been correlated with MMP-9 levels. Other investigators are looking into the inflammatory and autoimmune mechanisms involved in aneurysmal disease.6 Another area of research is in the molecular genetics of AAAs, …