Screening for abdominal aortic aneurysm using ultrasound can reduce risk of death

Guirguis-Blake JM, Beil TL, Senger CA, et al. Ultrasonography screening for abdominal aortic aneurysms: a systematic evidence review for the U.S. Preventive Services Task Force. Ann Intern Med. 2014;160:321-9.

Review question

Does an invitation to screening for abdominal aortic aneurysm (AAA) in people who have no symptoms reduce ruptures or death from ruptures?

Background

The aorta is the major blood vessel that supplies blood to the body and runs from the heart to the abdomen. An AAA is a weakening in the wall of the aorta. If an AAA ruptures, it causes internal bleeding, which can be fatal unless successfully treated with emergency surgery. People may not know that they have an AAA because they don’t always cause symptoms. Screening of people who don’t have symptoms using ultrasound can identify those with AAAs who can then be monitored more closely or treated, depending on the size of the AAA. Some people who have an AAA detected may choose to have elective surgery.

How the review was done

The researchers did a systematic review, searching for studies of screening for AAA published up to September 2013. They found 4 randomized controlled trials of 137,214 people (average age 68 to 73 years, 41% to 100% men). The key features of the studies were as follows:

• people 64 years of age or older who had no symptoms were invited for 1-time screening for AAAs;
• invitation for 1-time ultrasound screening (a painless, harmless test) was compared with no invitation to screening; and
• people with AAAs measuring 3.0 cm or more were monitored in 3 studies; in 1 study, results were sent to their family doctor for further management.

What the researchers found

The quality of the evidence was good for 2 trials and fair for 2 trials.

63% to 80% of those invited to have screening actually had an ultrasound.

Ultrasound screening for AAA:

• reduced death from AAA in 2 trials by 4 per 1,000 people (0.4%) and 6 per 1,000 people (0.6%) but did not reduce death in the other 2 trials; and
• reduced rupture of AAA in 1 trial by 6 per 1000 people (0.6%) but did not reduce rupture in the other trial.

Conclusion

In elderly people who do not have symptoms, an invitation to screening for abdominal aortic aneurysm using ultrasound can reduce death from AAA.

Ultrasound screening for abdominal aortic aneurysm (AAA) vs usual care