An abdominal aortic aneurysm (AAA) is stealthy. It rarely causes symptoms until it ruptures and becomes a life-threatening emergency. Ultrasound screening can catch aneurysms early, before they burst, but a lack of good research has made it hard for experts to offer comprehensive screeningguidelines—especially for women.
Recently updated recommendations from the U.S. Preventive Services Task Force (USPSTF) don’t deviate much from the previous ones released six years ago. They may leave women and older adults wondering whether they need to get screened.
An abdominal aortic aneurysm is a bulge in the aorta—the large vessel that carries blood from the heart to the abdomen and lower body. When the walls of the aorta weaken or become damaged—often caused indirectly by smoking—it can lead to an AAA. Eventually, the blood vessel can stretch andrupture, causing major internal bleeding, which is usually fatal. Most AAAs don’t have symptoms until they rupture, and only a small percentage of people with an intact AAA have symptoms like stomach pain.
Abdominal ultrasound screening can identify an AAA before it ruptures, potentially saving lives. Up to 81 percent of people whose aneurysms rupture don’t survive, says the USPSTF. Ultrasound is noninvasive,radiation-free, and nearly 100 percent accurate at picking up aneurysms.
Whether you need one of these tests depends on your risk factors. AAAs are most common in men over 65, former and current smokers, Caucasians, and people with a family history of the condition.
A gender gap
The new screening recommendations, published online in December 2019 by JAMA: The Journal of the American Medical Association, are virtually identical to the previous ones released in 2014. The USPSTF still recommends a one-time ultrasound screening for men ages 65 to 75 who are “ever smokers.” An ever smoker is considered to be someone who has smoked 100 or more cigarettes in his or her lifetime. Men in the 65 to 75 age range who have never smoked may need screening if they have risk factors like a close relative with an AAA.
In women, the guidance is less clear. Even though aneurysms rupture more often in women, and women account for more than 40 percent of AAA-related deaths, it’s been hard to issue screening recommendations because most of the research has been done in men.
The USPSTF doesn’t recommend screening for women ages 65 to 75 who never smoked, because their odds of getting an AAA are low. And, the task force says there isn’t enough evidence to advise women who have smoked or have a family history of AAA to be screened. Also left out are people over 75 because of insufficient evidence.
AAAs don’t always need treatment, but those that don’t will need to be closely monitored. More than 90 percent of the aneurysms detected on ultrasound measure less than 5.5 cm (2.2 inches) in diameter.
These small aneurysms are unlikely to rupture and can be monitored with ultrasounds once every six months to three years, depending on their size. Aneurysms larger than 5.5 cm or that grow quickly aremore likely to rupture and need repair. If you develop unexplained abdominal tenderness or back pain, contact your doctor; these could be signs of a rupture or an impending rupture.
Two types of procedures treat an AAA: open repair and endovascular aneurysm repair (EVAR). During an open repair, the surgeon makes an incision in the abdomen and replaces the diseased part of the aorta with a graft. In EVAR, a mesh tube called a stent is threaded through the artery in the groin to the damaged area to seal the aneurysm.
Most AAAs are repaired with EVAR unless they’ve ruptured. EVAR has a lower risk of death and complications in the short term, but the AAA can rupture again in the future, leading to the need for a second procedure. Open surgery is riskier, but the repair is more complete, and it may be best for younger people with a longer life expectancy.
Though women are far less likely to develop an aneurysm than men, treating them is trickier. Smaller aneurysms rupture more often in women than in men, but women are also more likely to have complications or die during repair, possibly because women tend to develop aneurysms at an older age than men.
The authors of the USPSTF guidelines say additional studies are needed to provide specific screening and treatment recommendations for women, older adults, and other groups for which robust evidence iscurrently lacking. If you’re an older woman or a man over 75 with a smoking history or a strong family history of AAA, you might want to discuss with your doctor whether you should consider the screening.
Preventing an aneurysm
Whether you’re at risk for an abdominal aortic aneurysm (AAA) or you already have one, your focus should be on prevention. The most effective way to avoid getting an aneurysm or stop an existing one from growing is to quit smoking.
Exercise may slow aneurysm growth, and it will also protect your heart. Moderate aerobic activities like jogging, biking, and swimming are safe for people with an AAA. Just avoid heavy weight lifting, especially while holding your breath, which could cause the aorta to tear.
This article first appeared in the March 2020 issue of UC Berkeley Health After 50.
Also see Screening Tests for Heart Disease.
Published March 24, 2020