Abdominal aortic aneurysm

Abdominal aortic aneurysm

An abdominal aortic aneurysm is a weakened and bulging area in the lower part of the aorta, the major blood vessel that supplies blood to the body. The aorta, about the thickness of a garden hose, runs from your heart through the center of your chest and abdomen. Because the aorta is the body's main supplier of blood, a ruptured abdominal aortic aneurysm can cause life-threatening bleeding. Although you may never have symptoms, finding out you have an abdominal aortic aneurysm can be frightening.

Most small and slow-growing abdominal aortic aneurysms don't rupture, but large, fast-growing abdominal aortic aneurysms may. Depending on the size and rate at which the aortic aneurysm is growing, treatment may vary from watchful waiting to emergency surgery. Once an abdominal aortic aneurysm is found, doctors will closely monitor it so that surgery can be planned if it's necessary. Emergency surgery for a ruptured abdominal aneurysm can be risky.

Causes:

Most aortic aneurysms occur in the part of your aorta that's in your abdomen. Although the exact cause of abdominal aortic aneurysms is unknown, a number of factors may play a role, including:

Tobacco use. Cigarette smoking and other forms of tobacco use appear to increase your risk of aortic aneurysms. In addition to the damaging effects that smoking causes directly to the arteries, smoking contributes to the buildup of fatty plaques in your arteries (atherosclerosis) and high blood pressure. Smoking can also cause your aneurysm to grow faster by further damaging your aorta.
High blood pressure. High blood pressure, especially if poorly controlled, increases the risk of developing an aortic aneurysm. This is because high blood pressure can damage and weaken your arteries.
Infection in the aorta (vasculitis). In rare cases, aortic aneurysm may be caused by an infection or inflammation that weakens a section of the aortic wall.

Aneurysms can develop anywhere along the aorta, but when they occur in the upper part of the aorta, they are called thoracic aortic aneurysms. More commonly, aneurysms form in the lower part of your aorta, and are called abdominal aortic aneurysms. Rarely, an aneurysm can occur in between the upper and lower parts of your aorta. This type of aneurysm is called a thoracoabdominal aneurysm.

Treatments and drugs:

Here are the general guidelines for treating abdominal aortic aneurysms:

Small aneurysm. If you have a small aortic abdominal aneurysm — about 1.6 inches, or 4 centimeters (cm), in diameter or smaller — and you have no symptoms, your doctor may suggest a watch-and-wait (observation) approach, rather than surgery. In general, surgery isn't needed for small aneurysms because the risk of surgery outweighs the risk of rupture.

If you choose this approach, your doctor will monitor your aneurysm with periodic ultrasounds, usually every six to 12 months and encourage you to report immediately if you start having abdominal tenderness or back pain - potential signs of a dissection or rupture.
Medium aneurysm. A medium aneurysm measures between 1.6 and 2.2 inches (4 and 5.6 cm). It's less clear how the risks of surgery versus waiting stack up in the case of a medium-size aortic abdominal aneurysm. You'll need to discuss the benefits and risks of waiting versus surgery and make a decision with your doctor.
Large, fast-growing or leaking aneurysm. If you have an aneurysm that is large (larger than 2.2 inches, or 5.6 cm) or growing rapidly (more than 0.5 cm over six months), you'll probably need surgery. In addition, a leaking, tender or painful aneurysm requires treatment. There are two types of surgery for abdominal aortic aneurysms.

Open-abdominal surgery to repair an abdominal aortic aneurysm involves removing the damaged section of the aorta and replacing it with a synthetic tube (graft), which is sewn into place, through an open-abdominal approach. With this type of surgery, it will likely take you several months to fully recover.

Endovascular surgery is a less invasive procedure sometimes used to repair an aneurysm. Doctors attach a synthetic graft to the end of a thin tube (catheter) that's inserted through an artery in your leg and threaded up into your aorta. The graft — a woven tube covered by a metal mesh support — is placed at the site of the aneurysm and fastened in place with small hooks or pins. The graft reinforces the weakened section of the aorta to prevent rupture of the aneurysm.

Recovery time for people who have endovascular surgery is shorter than for people who have open-abdominal surgery — about one or two weeks compared with six weeks for open surgery.

The options for treatment of your aneurysm will depend on a variety of factors, including location of the aneurysm, your age, kidney function and other conditions that may increase your risk for surgery or endovascular repair.