Abdominal aortic aneurysms: screenings are the best way to defuse a silent killer

Nearly 15,000 Americans die each year from a ruptured abdominal aortic aneurysm. Until it ruptures, this bulge in the main blood vessel that runs from the heart rarely causes any symptoms for the unsuspecting patient. However, it is a ticking time bomb.

When the abdominal aortic aneurysm is repaired electively, before rupture, the survival rate is 95 percent. Unfortunately, if the aneurysm ruptures, the patient survival rate drops to only 15 percent to 20 percent.

With these medical facts, Gilbert Upchurch Jr., M.D., of the University of Michigan Health System, recommends that men and women who are at risk for developing an abdominal aortic aneurysm talk with their health care professional about screening for this silent killer.

"Most patients who have an abdominal aortic aneurysm don’t even know it. Traditionally, there’s no pain or other symptoms associated with the condition," says Upchurch, who is a vascular surgeon and assistant professor of surgery at U-M Medical School.

An aneurysm is a bulge or ballooning of the aorta, which is the main blood vessel that runs from the heart, supplying blood to the rest of the body. Most abdominal aneurysms occur in that portion of the aorta that is below the kidneys.

Upchurch says that in the elective setting, patients who undergo a repair have a 95 percent chance of survival. It’s a different story for those with a rupture. Half of these patients don’t even survive long enough to reach the operating room. Patients with ruptured abdominal aortas who undergo surgery only have a 15 or 20 percent chance of surviving the operation and living 30 days.

"We base elective surgery primarily on the size of the aneurysm," says Upchurch. "There have been a number of studies looking at using size to predict aneurysm rupture. We now use roughly five and a half centimeters as the size at which we repair aneurysms."

Sometimes, patients learn by accident that they have an abdominal aortic aneurysm. Since the condition has few, if any, outward symptoms, testing such as an x-ray or ultrasound for another condition may turn up the dangerous aortic bulge.

The key is to detect the aneurysm before it ruptures, and to make sure their care is with a doctor and hospital that are experienced in surgeries to correct abdominal aortic aneurysms.

"Screening is simple. We use an abdominal ultrasound, so there’s no radiation involved. Anyone at risk for this kind of aneurysm should be talking to their health care providers about a screening," Upchurch says.

Here are some important facts about abdominal aortic aneurysms, including risk factors:

• Ten percent of males over the age of 70 have an abdominal aortic aneurysm.
• Nearly 15,000 Americans die each year from an abdominal aortic aneurysm.
• In 2003, it was the 14th leading cause of death in the United States.
• Men are four times more likely than women to develop abdominal aortic aneurysms.
• These types of aneurysms tend to develop in women ten years later than they do in men.
• Hospitals that perform 30 or more operations a year on abdominal aortic aneurysms have a higher survival rate for these patients.
• The number of cases a surgeon performs annually is also an important factor in patient survival rates.
• Once detected, aneurysms too small for surgery should be monitored annually.

Risk factors include:
• History of hypertension
• Smoking
• Having a close relative with an abdominal aortic aneurysm
• Emphysema or chronic obstructive pulmonary disease

For more information:

U-M Adult Health Advisor: Abdominal Aortic Aneurysmectomy and Bypass
www.med.umich.edu/1libr/aha/aha_aaa_car.htm

U-M Vascular Surgery: Abdominal Aortic Aneurysms
www.med.umich.edu/surg/vas/aneurysms.html

Medicine at Michigan: Silent Time Bombs
www.medicineatmichigan.org/magazine/2003/fall/cvc/upchurch.asp

Medline Plus: Aneurysms
www.nlm.nih.gov/medlineplus/aneurysms.html

Society of Interventional Radiology: Stent-Graft Repair of Abdominal Aortic Aneurysms
www.sirweb.org/patPub/abdominalAorticAneurysms.shtml