No More Effective Than Aspirin, Study Claims : Surgery to Prevent Strokes Minimized
In an extensive study involving 1,377 stroke-prone patients at 70 medical centers, researchers have concluded that a widely performed operation intended to prevent strokes is no more effective than aspirin.
The operation, called an extracranial-intracranial arterial bypass, is intended to increase the flow of blood to the brain by implanting an artery from the scalp into a major brain artery that has become obstructed. According to the advocates of the operation, the resulting increased blood flow helps to prevent strokes by supplying the brain with the needed oxygen and nutrients that are in short supply and make the patient vulnerable to a stroke.
But a scientifically controlled trial reported in today’s New England Journal of Medicine concludes that both nonfatal and fatal strokes occurred more frequently in the patients who underwent the operation, and that their survival was no longer than that of patients who were treated with medication, usually aspirin.
The procedure was first performed in 1967 and quickly gained popularity when the initial reports led many neurosurgeons to believe the surgery could benefit patients.
In order to test the ability of the operation to prevent strokes, patients in the study who recently had had a nondisabling stroke or who showed clinical signs that they were stroke-prone were randomly assigned to receive either medication alone or medication plus the bypass operation.
The 1,377 patients were then followed for an average of 55 months, and the results of the study were analyzed.
Although a number of studies previously had claimed favorable results after the surgery, they involved only surgical patients and focused on such things as whether blood flow in the brain increased or whether other physiological or psychological changes believed to be beneficial were observed.
Some of these studies showed that the operation did have the desirable effect of increasing the supply of oxygen and nutrients to the brain. But those studies did not involve a controlled comparison with similar patients on whom the operation was not performed.
The latest study was conducted by researchers at two Canadian medical centers, the University of Western Ontario in London and McMaster University in Hamilton. It was funded by the U.S. National Institute of Neurological and Communicative Disorders and Stroke. The patients were treated at participating centers in Canada, Europe, Japan and the United States, including Los Angeles and San Francisco.
No Evidence of Decrease
Although the investigators had originally hypothesized that the operation would result in a one-third reduction in fatal and nonfatal strokes, they concluded that “there was no evidence that surgery decreased the number of strokes.”
According to Dr. Fred Plum of the New York Hospital-Cornell Medical Center, the study results have important implications for controlling the cost of health care and for the need to evaluate other procedures for which objective supporting data is lacking.
“It is high time that governmental and third-party underwriters heeded the results of this kind of analysis and removed useless procedures from the list of reimbursable medical treatments,” Plum declared in an editorial accompanying the journal report.
“Even more important for future patient care and health costs is the demonstration that funds invested in carefully conducted prospective studies can evaluate potentially expensive new treatments (and, presumably, diagnostic measures as well) before they add their economic load to the health-care budget.”
$9-Million Study
Plum said that although the study cost $9 million, “if the success of the present study encourages similar analyses of other disorders in which the benefits of expensive and risky treatments are uncertain, the cost savings could be very large indeed.”
Dr. Michael Walker, director of the stroke and trauma program at the National Institute of Neurological and Communicative Disorders and Stroke, estimated that about 3,000 bypasses are performed each year in this country at a cost of at least $15,000 each.
In Los Angeles, Dr. Bruce Dobkin, medical director of the stroke unit at Daniel Freeman Memorial Hospital, one of the participating centers, said that he had trouble finding enough neurosurgeons to take part in the study because so many of them believed in the operation’s benefits.
“In a randomized trial, they felt they could not withhold a procedure that they felt had promise,” he said in a telephone interview. “But it will be tougher and tougher for surgeons to do (the operation) now.”
