Can medication slow growth of abdominal aortic aneurysms?

An abdominal aortic aneurysm is a bulge in a section of the aorta, the body's main artery. The risk of a rupture is unpredictable, and few patients survive when they do.

The U-M's Frankel Cardiovascular Center is the only health center in the state selected to participate in the national clinical trial investigating what could be the first medical therapy available in the high-stakes course of treating aneurysms.

Surgical repair may become necessary when an aortic aneurysm reaches a certain size or interferes with surrounding blood vessels or organs, but surgery is not an option for all aortic patients.

"It's a really exciting trial examining options for the patients who are relegated to watching and waiting," says University of Michigan vascular surgeon Jonathan Eliason, M.D., associate professor of surgery. "If this medicine is effective in slowing aneurysm growth rates, it could revolutionize our treatment of AAAs."

The clinical trial Non-Invasive Treatment of Abdominal Aortic Aneurysms (N-TA^3CT) will determine whether treatment with doxycycline, a microbial drug that in animal studies inhibited the action of matrix metalloproteinase (MMP), an enzyme linked to the development of AAAs, will lead to reduced growth of an aneurysm.

"The aim is to see if the data gained from animal studies for slowing aneurysm growth holds true for humans," says Eliasion.

A normal abdominal aorta is approximately 2.0 cm in diameter -- about the size of a quarter -- but an aneurysm puts stress on the artery walls. The risk of rupture for an AAA over 5.5 cm in diameter is 9 to 10 percent, and over 7 cm the risk increases to more than 30 percent.

AAA is more common in men and in those age 65 and older. According to the Centers for Disease Control and Prevention, the most effective way to prevent aortic aneurysms is reducing risk factors including quitting smoking and controlling high blood pressure and high cholesterol.