Men between the ages of 65 and 75 who are or have been smokers should have a one-time ultrasound to screen for abdominal aortic aneurysm, according to a new recommendation from the U.S. Preventive Services Task Force.

Nearly 70 percent of men in this age group have smoked and would benefit from routine screening to check for aneurysms.

This is the first time the Task Force has recommended screening for abdominal aortic aneurysms. When the Task Force last reviewed the topic in 1996, the group found insufficient evidence to screen for such aneurysms, but new evidence has shown that screening and surgery to repair large abdominal aortic aneurysms are effective at reducing the number of deaths in men caused by this condition. Estimates indicate that between 59 percent and 83 percent of patients with ruptured abdominal aortic aneurysms die before reaching the hospital and having surgery.

Men ages 65 and older who currently are or have been regular smokers are at the highest risk for abdominal aortic aneurysm. Few studies have been conducted in women, and the published research indicates that women are at low risk for aneurysms. Death from an aneurysm is a rare event in women, and most of these deaths occur in women older than 80.
The Task Force found no evidence of benefit from routine screening for abdominal aortic aneurysm in all women and concluded that potential harms of screening, from mortality and complications of surgery for aneurysms, outweighed potential benefits.

Because abdominal aortic aneurysm is significantly less likely to occur in people who have never smoked, the Task Force also found that screening them for abdominal aortic aneurysm would have little net benefit. Therefore, the Task Force made no recommendation either for or against routine screening for abdominal aortic aneurysm in men between the ages of 65 and 75 who have never smoked.

Abdominal aortic aneurysm is an abnormal ballooning of the aorta that occurs in the abdomen. Each year, such aneurysms cause approximately 9,000 deaths in the United States. This number may be an underestimate since the majority of people with ruptured aneurysms die before reaching a hospital, and their deaths may be attributed to other causes.

“ This is an important recommendation because evidence now exists that screening high-risk men for abdominal aortic aneurysms can reduce deaths from aneurysm,” said Task Force chair Ned Calonge, who also is Chief Medical Officer and State Epidemiologist for the Colorado Department of Public Health and Environment. “ One of the most important things men and women can do for their health is to never start smoking and to quit if they do. People who have a family history and might be at risk for abdominal aortic aneurysm should discuss their concerns with their physicians.”

The Task Force found evidence that surgery to repair the aorta in people with an aortic diameter of at least 5.5 centimeters is effective to reduce the number of deaths caused by abdominal aortic aneurysm. Elective open surgery has an in-hospital mortality rate of 4.2 percent. Endovascular repair ( EVAR ) of abdominal aortic aneurysms has been shown to have short-term benefits compared with open surgical repair, but the long-term effectiveness and harms of EVAR are not known.

The Task Force, which is supported by AHRQ, is the leading independent panel of private-sector experts in prevention and primary care and conducts rigorous, impartial assessments of the scientific evidence for a broad range of preventive services. The Task Force based its conclusions on a report from a research team led by Craig Fleming, at AHRQ's Oregon Evidence-based Practice Center in Portland.

Task Force grades the strength of the evidence from “A” ( strongly recommends ), “B” ( recommends ), “C” ( no recommendation for or against ), “D” ( recommends against ) or “I” ( insufficient evidence to recommend for or against screening ).

The Task Force recommends a one-time screening by ultrasonography for abdominal aortic aneurysm in men between the ages of 65 and 75 who are or were smokers ( a “B” recommendation ).
The Task Force makes no recommendation for or against screening men between 65 and 75 who never smoked ( a “C” recommendation ).
The Task Force recommends against screening for abdominal aortic aneurysm in women ( a “D” recommendation ).

Source: Annals of Internal Medicine, 2005


XagenaMedicine2005