Abstract
Abdominal aortic aneurysm is a significant cause of morbidity and mortality. Although
descriptions of aneurysmal disease date back to 2000 BC, scientific approaches to
understanding the pathogenesis and management of abdominal aortic aneurysms date back
less than 200 years. Abdominal aortic aneurysms account for two-thirds of large series
of aneurysmal disease. The incidence of abdominal aortic aneurysm ranges from 1–16%.
The highest incidences occur in the first-degree relatives of individuáls with an
abdominal aortic aneurysm. Higher incidences are identified in white males, in patients
with chronic obstructive lung disease, and in smokers. Pathologically identified is
the destruction of medial and adventitial elastin and collagen as well as destruction
of medial smooth muscle cells. The infiltration by lymphocytes and macrophages leads
to release of cytokines and matrix metalloproteinases. Inherited aspects that have
been identified involve antitrypsin deficiency. The role of simple screening by ultrasound
or CT has proved cost effective to identify patients with abdominal aortic aneurysm
and to follow progression. In an effort to prevent the high morbidity and mortality
costs associated with ruptured abdominal aortic aneurysm, several management routes
have emerged. The indications for management include size as well as associated conditions
that increase risk of rupture. The risks and complications of any management approach
are balanced against the risks of rupture and against the risks of management at a
stage of increased physiological risks with increasing age. Improvements in mortality
and morbidity with open surgical repair are the result of improved surgical and anesthetic
techniques. Beginning in 1990 the endovascular repair of abdominal aortic aneurysms
has proceeded. The key factors involved in successful use have included efforts to
achieve proximal and distal endograft fixation and sealing with the aortic wall at
the proximal neck and distally within the aorta or iliac arteries. The experience
and attributes of available prostheses are presented. The nature of endoleaks and
their management are reviewed. The possible pharmacologic approaches to prevent aneurysm
progression include the use of tetracyclines and COX-2 inhibitors to inhibit matrix
metalloproteinase 9, the use of ACE inhibitors to suppress elastase activity and statins
to decrease the inflammatory process. Although many questions regarding abdominal
aortic aneurysms have answers, many more await answers.
