Older men should be screened for aortic aneurysm

Older men, particularly those who have smoked cigarettes, should undergo screening for abdominal aortic aneurysm (AAA), according to a report in the Annals of Internal Medicine.

"Once in a great while, evidence becomes available to add a new screening test to the periodic health examination," Dr. Frank A. Lederle from University of Minnesota and VA Medical Center, Minneapolis, told AMN Health. "This evidence is now available for ultrasound screening for AAA. We should now think of this test for routine use in the appropriate population, just like mammography or fecal occult blood testing."

An AAA occurs when the wall of the aorta - the body's largest artery that carries blood from the heart - is stretched or weakened as it passes through the abdomen. Blood pumping through the artery can cause the weakened wall to balloon out and possibly rupture, causing immediate death in about 65 percent of patients. Only half of those who make it to surgery after a rupture survive.

Lederle and colleagues reviewed the available evidence on the benefits and harms of population-based AAA screening for the U.S. Preventive Services Task Force (USPSTF).

Four AAA screening trials in men uniformly found an association between screening and a reduction in AAA-related deaths, the authors report, but the total number of deaths from all causes was not significantly reduced.

For women, there were no differences in AAA-related deaths or deaths from all causes in those who did or did not have screening for AAA, the report indicates.

Advanced age and a history of smoking contributed to the risk of AAA and enhanced the benefits of ultrasound screening for AAA, the researchers note. Repeated screening after an initial negative ultrasound result did not significantly reduce mortality, the investigators report, though there were no significant harms associated with AAA screening.

Based on these findings, the USPSTF recommends "one-time screening for abdominal aortic aneurysm by ultrasonography in men age 65 to 75 years who have ever smoked."

The USPSTF makes no recommendation regarding such men who have never smoked and recommends against routine screening for AAA in women.

"The USPSTF took a conservative stand on the evidence," Lederle said. "It would have also been reasonable to recommend screening for all men aged 65-75, regardless of smoking status, as this is the group included in the randomized trials in which the benefit was shown and on which the recommendation was based."

"However," Lederle explained, "USPSTF recommendations are often converted directly into performance standards, which essentially mandate screening. It is probably most reasonable to leave screening of men who never smoked to the discretion of physician and patient."

"Smoking is both an important cause of AAA and a factor in AAA enlargement, so smoking cessation should be stressed," Lederle added. "Unfortunately, no drugs have been shown to slow progression of AAA, though research in this area is ongoing."