Determining Rupture Risk of Large Aneurysms

A new study showing that the diameter of an abdominal aortic aneurysm (AAA) is the best indicator of rupture risk may help doctors decide when it is safe to operate on high-risk AAA patients. The study was reported in the June 12, 2002, issue of the Journal of the American Medical Association (JAMA).

Researchers observed 198 AAA patients and determined that the risk of rupture increases dramatically as the aneurysms develop beyond 5.5 cm in diameter. However, surgery for some patients may be a greater risk than the aneurysm. As aneurysms grow larger, they become more dangerous, so that surgery eventually becomes a lesser risk. Before this study, doctors could not accurately tell where the risk threshold was between operation and the aneurysm. Now, doctors can make a more accurate estimate of risk, based primarily on the size of the aneurysm.

The study was conducted by researchers at the US Veterans Affairs (VA) Medical Center in Minneapolis (MN, USA). An upcoming study will compare standard AAA repair with endovascular repair, a new method that repairs the AAA from inside the aorta through a small incision in the groin. Researchers hope to determine which method has the best long-term results.

"This study will also help elective-surgery patients make better-informed decisions,” said Frank Lederle, M.D., lead author. "Doctors can now give their patients specific figures depicting the risks of surgery based on the size of an aneurysm.”