Abdominal aortic aneurysm

DEFINITION OF ABDOMINAL AORTIC ANEURYSM

An abdominal aortic aneurysm is an enlarged 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.

Depending on the size and rate at which your abdominal 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 aortic aneurysm can be risky.

Here are the general guidelines for treating abdominal aortic aneurysms.

Small aneurysm

If you have a small abdominal aortic 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 likely 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.

Medium aneurysm

A medium aneurysm measures between 1.6 and 2.1 inches (4 and 5.3 cm). It's less clear how the risks of surgery versus waiting stack up in the case of a medium-size abdominal aortic aneurysm. You'll need to discuss the benefits and risks of waiting versus surgery and make a decision with your doctor. If you choose watchful waiting, you'll need to have an ultrasound every six to 12 months to monitor your aneurysm.

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 (grows more than 0.5 cm in 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 a month or more 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. However, follow-up appointments are more frequent because endovascular grafts can leak. Follow-up ultrasounds are generally done every six months for the first year, and then once a year after that. Long-term survival rates are similar for both endovascular surgery and 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 of surgery or endovascular repair.