Standards: New Approach to Aneurysms

By ERIC NAGOURNEY
New York Times 7-22-2003

mall aneurysms of the brain, which doctors have generally let alone, should be repaired in many cases, a recent study advises.

Until now, doctors have usually monitored aneurysms up to diameters of 10 millimeters, or about half an inch. The concern has been that the treatment may be more dangerous than the aneurysm.

But writing in The Lancet, researchers said that the guidelines should be revised and that aneurysms seven millimeters in diameter or greater should be treated in many situations.

Aneurysms occur when part of a brain artery weakens and balloons. About 1 in 15 Americans are believed to have them. The trouble comes when the aneurysms burst, as they do in about 30,000 cases a year, causing death or injury.

The report suggesting new guidelines was prepared by investigators with the International Study of Unruptured Intracranial Aneurysms and was intended to help doctors to decide when treatment is appropriate and what method is best to use.

The researchers looked at the experiences of more than 4,000 patients from 1991 to 1998 who had been treated or monitored.

Most patients in the United States are now treated surgically: doctors open the skull and put a clamp on the affected area. But increasingly, nonsurgical endovascular procedures are used, with small coils placed at the aneurysm site with a catheter.

Dr. Charles M. Strother, president of the American Society of Neuroradiology, said that deciding whether to treat an aneurysm had always been a tough call.

"This study, I think, is a very good study," Dr. Strother said. "It adds some objective criteria that we can try to factor in."

Nevertheless, he said, many questions remain.