FRIDAY, March 19, 2004 (HealthDayNews) -- Doctors aren't doing the artery-clearing operations called carotid endarterectomies often enough or quickly enough for many people who suffer a temporary blockage of a brain artery known as a "mini-stroke," a British study finds.
The study includes data on about 5,900 people in two major trials in Europe and North America, which compared the risk of stroke when the procedure was or wasn't done, the risk of the operation itself and the overall benefit from surgery for the patients.
It concludes the benefit is greatest for old men, those 75 and older, especially when the procedure is done in the weeks immediately after a blockage -- formally known as a transient ischemic attack (TIA) and informally known as a "warning stroke" -- occurs.
"Benefit is particularly dependent on the delay to surgery after the presenting event," says Dr. Peter M. Rothwell, director of the Oxford University Stroke Prevention Research Unit and lead author of a paper on the study in the March 20 issue of The Lancet. "Ideally, the procedure should be done within two weeks."
Carotid endarterectomy is the most common procedure in neurosurgery. It is done to clear the carotid arteries, the main blood vessels to the brain, of fatty deposits that can build up until they block an artery, causing a stroke.
The studies included patients who had had some blockage involving the carotid artery: a non-disabling stroke, a TIA or an obstruction of blood to the retina.
For patients with the most severe artery blockage, surgery in the first two weeks reduced the incidence of a second stroke or death in the following five years by more than 30 percent. The risk was reduced by only 17.6 percent when the operation was done two to four weeks later, and by 11.4 percent when the wait was four or more weeks.
Surgeons often are reluctant to perform the procedure immediately after a TIA or similar event for fear the risk of surgical damage is too great and waiting is better. Asked whether the study will put that fear to rest, Rothwell says, "Yes."
The risk of stroke or death is higher immediately after carotid endarterectomy is done, the study shows, but the longer-term benefits outweigh that risk.
But another reason for delay is that "patients do not always seek medical attention immediately after a TIA or stroke," he says.
"There is therefore a need to educate the public about the symptoms of warning strokes and TIAs so that people seek medical attention immediately," Rothwell says.
There have been "several suggestions" that quick endarterectomy is advisable, says Dr. Marc R. Mayberg, chief of neurosurgery at the Cleveland Clinic Foundation and chairman of the American Heart Association's Stroke Council. "But it has never been shown in this kind of approach, using data from large, randomized trials," he adds.
"Physicians have always taken the approach that this kind of procedure is one that can be done at leisure," Mayberg says.
But he favors quick surgery, based in large part on his participation in one of the studies cited in the new report.
"My approach has been to treat patients the same day, if I can," when they report symptoms of a TIA, Mayberg says.
"All groups benefit from early surgery," Rothwell says. "The difficulty is in working out in whom it is still worth operating among patients who present late."
A guide to carotid endarterectomy can be found at the National Institute of Neurological Disorders and Stroke, which also has a page on TIAs.