Brain surgery to route blood flow around clogged carotid arteries doesn’t help patients more than drug therapy, again calling into question aggressive treatment for brain blockages, researchers say.
A study published Tuesday in the Journal of the American Medical Association is the second to find the bypass procedure ineffective. The trial was halted early after independent monitors concluded it was futile to continue. A third trial released in September found stents used to prop open clogged brain arteries triggered more strokes than drug treatment.
The latest study looked at patients with blockages in the internal carotid arteries with symptoms caused by low blood flow to the brain. Those treated with bypass surgery were more likely to have a stroke within 30 days than those given only drugs to break up any blood clots. About one in five patients in both groups suffered a major stroke within two years.
Blockages in the internal carotid arteries cause about 10 percent of “mini-strokes,” or transient ischemic attacks that occur when blood to the brain is temporarily restricted, and up to 25 percent of major strokes caused by clots, according to researchers led by William Powers, from the University of North Carolina School of Medicine in Chapel Hill. Restoring consistent blood flow to the brain with surgery or stents seemed logical, and both approaches have gained momentum in recent years.
Surgery and stents used inside the skull, called endovascular therapy, haven’t been proven to reduce strokes, avert deaths or improve health, wrote Joseph Broderick from the University of Cincinnati College of Medicine and Philip Meyers from Columbia University in New York in an editorial accompanying the study. A generic drug known as t-PA that breaks up blood clots is the only method proven effective for stroke patients, and it was recommended for all patients in the study.
The results show federal regulators and those running Medicare, the government’s health insurance program for the elderly and disabled, should require more evidence before approving new treatments and paying for them, Broderick and Meyers said.
“Physicians who provide care for patients with stroke must recognize the current lack of evidence” for benefit from the surgical treatments and enroll patients in studies, they said. “If intravenous t-PA is clinically equivalent to endovascular therapy, society will have to weigh the substantially increased costs for equal clinical benefit. If these devices produce better clinical outcomes, appropriate reimbursement, even for more expensive endovascular interventions, should be promptly instituted.”
The National Institute of Neurological Disorders and Stroke funded the study.