Thoracic or abdominal aortic aneurysms that are large, causing symptoms, or rapidly getting bigger are considered at risk of rupturing. Surgery is usually recommended if any one of these factors is present.Your doctor will consider:

• Whether you need urgent surgery.
• Whether you will be able to withstand a major surgery.
• Whether you can avoid surgery, at least for the present.

When making a decision about surgery for an aortic aneurysm, the benefits in relation to the risks of surgery must be considered, as well as the risks of major surgery. People who are at significant risk from surgery may elect to use medical management or another technique such as a stent graft procedure.

Your doctor will closely monitor the size and rate of growth of smaller aneurysms using abdominal ultrasound, computed tomography (CT) scan, or other imaging tests.

Abdominal aortic aneurysms

In men, surgery is typically recommended for abdominal aortic aneurysms that are causing symptoms or that are 5.5 cm or larger in diameter. In women, surgery may be recommended for smaller aneurysms. Some doctors perform surgery when the aneurysm is smaller, although the risk of rupture is considered low for aneurysms less than 5.5 cm in diameter.^{4, 5}

Surgery is also recommended for small aneurysms that have grown more than .5 cm within 6 months.

Thoracic aortic aneurysms

Your doctor will recommend that you have surgery for a thoracic aortic aneurysm based on the following guidelines:

• If the aneurysm is located where the aorta ascends up out of the heart, surgery is recommended when it reaches 5.5 to 6.0 cm in diameter.
• If the aneurysm is located where the aorta begins to descend, surgery is recommended when it reaches 6.0 cm in diameter.
• In those with Marfan's syndrome, surgery is recommended when the aneurysm reaches 5.5 cm in diameter.
• If the aneurysm causes significant aortic regurgitation, surgery is recommended.

Surgeons and institutions around the country have differing experiences with aortic aneurysms and may follow different protocols in the treatment of the disease. The most important factor to remember is that every case is unique and complicated. You should work with your doctor to decide which treatment is best for you.

If surgery is chosen, your doctor will evaluate your overall health, including assessments of your heart, lungs, and circulatory system, the kidneys, and the gastrointestinal system. The decision whether to have surgery is based on the outcome of these evaluations. The risk of death or injury during the operation increases if other disease is present.

• If the evaluation of your heart indicates that you have significant heart disease, you should undergo coronary artery bypass surgery (CABG) or coronary angioplasty prior to repairing an aortic aneurysm. This is because coronary artery disease is the most important underlying factor contributing to complications, such as heart attack, in the period before and after the operation.⁸ Other complications, such as stroke and infection of the graft, can also occur.
• Kidney failure, chronic lung disease, and cirrhosis of the liver may double or triple the risk of death and complications during the operation period.⁸
• Smoking and high blood pressure put a person at a higher risk for complications from surgery. They are also risk factors for the rupture of an abdominal aortic aneurysm.

It is not an option to wait until an aneurysm has ruptured before surgery is done. Most people who have a ruptured aortic aneurysm die. Surgery for an already ruptured aneurysm may be tried but is not usually successful due to excessive, rapid blood loss.