SCIENCE / MEDICINE : Operation Found Unnecessary

Small, bulging weak spots in the main blood vessel in the abdomen do not need to be routinely repaired in most patients, unlike large weak spots, which are in danger of bursting, a study concludes.

Surgery for these common defects, known as abdominal aortic aneurysms, has grown dramatically in recent decades and is now performed on about 40,000 people in the United States each year.

Experts agree that large aneurysms should be fixed, because they may burst, causing catastrophic bleeding and death. But some doubt lingers over whether smaller aneurysms must be immediately repaired.

The latest study, conducted at the Mayo Clinic, found that most abdominal aortic aneurysms expand slowly, and small ones pose little risk of rupture.

“Our data indicate that all small aneurysms do not need to be routinely repaired,” said Dr. John W. Hallett Jr., senior author of the study, which was published the New England Journal of Medicine.