Bypass surgery for stroke prevention hasn't been performed in U.S. hospitals since 1985. But it's finding new life in a clinical study at UT Southwestern Medical Center at Dallas.
As part of the Carotid Occlusive Surgery Study, UT Southwestern physicians will revive the lost art of stroke bypass to find out if the surgery can help prevent certain types of the brain attacks that involve impairment of cerebral blood circulation. The procedures lost favor 17 years ago after a study in The New England Journal of Medicine showed they had no benefit to patients.
But some doctors now question the validity of that research, saying advanced diagnostic equipment wasn't used and patients not well-suited for the surgery were chosen.
The National Institutes of Health has stepped in and funded a 10-center study to determine, again, whether the surgery is effective. This trial will include positron-emission scanning as well as evaluations of oxygen extraction rates in the brain, two predictors of whether stroke bypass surgery might be beneficial for a patient.
At UT Southwestern, the same surgery that was used for the stroke bypasses years ago is currently used for people with unusually large aneurysms or moyamoya syndrome, a rare disease of the blood vessels in the brain. Since so few doctors today know how to perform the now-rare and tedious stroke bypass, UT Southwestern physicians expect to provide a majority of patients for the trial.
Dr. Thomas Kopitnik will lead the study with Dr. Hal Unwin, associate professor of neurology who heads UT Southwestern's stroke programs.
Surgeons performing the surgery literally bypass blocked or strained arteries by using other vessels in the brain to direct blood flow. Ten to 15 percent of strokes, or as many as 61,000 a year in the United States, begin in the carotid artery.
"Without this procedure, there's been very little we could do for patients with a blocked carotid artery," Kopitnik said. He hopes the trial will answer new questions about an old procedure.
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