DEFINATION: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.