Abdominal Aortic Repair

An abdominal aortic aneurysm (AAA) is defined as a permanent dilation of the abdominal aorta, with a diameter greater than 3 cm or a diameter greater than 50% of the aortic diameter at the level of the diaphragm. If left untreated, progressive vessel wall degeneration leads to dilation and thinning of the vessel. Eventually, these changes can result in the rupture of the AAA. AAA prevalence and incidence rates have decreased over the last 20 years, both in developed and in developing countries. This decrease has been attributed partially to the decline in smoking. Prevalence is negligible before the age of 55 to 60 years, and after that, the prevalence increases with age. AAA prevalence is up to fourfold more in men (between 1.3% and 12.5%) than women (between 0.0% and 5.2%). The risk of rupture increases with the size of the aneurysm: the 5-year risk for aneurysms less than 5 cm is 1% to 2%, whereas it is 20% to 40% for aneurysms greater than 5 cm in diameter. Abdominal aortic aneurysm represents about 1% of deaths in males over the age of 65 and is the tenth leading cause of death in men 65 years of age or older. The mortality rate of ruptured abdominal aortic aneurysm is over 80%. Early diagnosis and treatment, therefore, is very important before its rupture. To this day, treatment for AAA relies on two different surgical methods: Endovascular placement of an aortic stent graft (EVAR) and open surgical repair of AAA (OSR). Open surgical repair is a major operation involving the excision of dilated area and placement of a sutured woven graft. The surgery may be performed electively or under emergent situations. Unlike OSR, the EVAR is meant to seal the sac from the inside of the aneurysm, while the aneurysm wall is left untouched. The paradigm is therefore changed from replacing the aneurysm to excluding it from the systemic circulation.  A serial noninvasive follow-up of small aneurysms (less than 5 cm) is an alternative to surgery. Ultrasonography is the recommended modality for surveillance; it should be performed every three years for aneurysms 3 to 3.9 cm in diameter, or annually for aneurysms 4.0 to 4.9 cm. There is no specific medication or other therapy that can be recommended to reduce the rate of aneurysm growth. Moreover, beta-adrenergic blockers and renin-angiotensin inhibitors, have not proven effective in reducing the rate of aneurysm growth. Lifestyle changes, such as exercise, also have not demonstrated a reduction in the aneurysmal growth rate. However, smoking cessation leads to a reduction in aneurysmal growth rate, as well as the risk of aneurysm rupture. Abdominal aortic aneurysm patients’ have a significant risk for future cardiovascular events that should be addressed. Recommendation of a healthy lifestyle (including exercise and a healthy diet) and blood pressure control, statins, and antiplatelet therapy, should be considered in all patients with abdominal aortic aneurysms.