The University of Iowa
The University of Iowa News Services Home News Releases UI in the News Subscribe to UI News Contact Us

University of Iowa News Release

July 6, 2004

UI Study Examines Brain Bypass For Possible Stroke Prevention

Neuroscientists at University of Iowa Hospitals and Clinics are helping lead a five-year, $17 million, multi-center study of the potential effectiveness of a brain bypass surgery in preventing people from having a second stroke.

Each year, about 80,000 Americans develop a complete blockage in their internal carotid artery, one of the main blood vessels that supply the brain with blood. That blockage can result in either a stroke or a transient ischemic attack, a milder form of stroke. Despite pharmaceutical advances, these people face a 25 percent risk for having another stroke within two years.

"At the moment, these patients don't do very well, even with treatment with the best medical therapies available," said Patricia Davis, M.D., UI associate professor of neurology. "We want to find out if this brain bypass surgical technique can change that situation."

Brain bypass surgery was originally developed and tested in the 1970s. Specialists abandoned it in the mid-1980s because research did not find a clear-cut benefit to patients.

The more recent development of performing positron emission tomography (P.E.T.) may help overcome that shortcoming. P.E.T. technology obtains images of the brain, which detect if there is adequate blood flow to brain and help predict who might benefit from brain bypass surgery and who will not.

Studies show that patients with a completely blocked internal carotid artery can actually develop a natural bypass, where smaller blood vessels take over the function of the clogged carotid artery. Researchers found that 26 percent of people who did not develop a natural bypass had a second stroke on the same side of the brain within two years, compared to only about 5 percent of people who did develop a natural bypass.

"The bottom line is that patients who don't develop this natural bypass do very poorly if they don't receive some kind of treatment," said Patrick Hitchon, M.D., UI professor of neurosurgery. "We think that by using P.E.T. scans we can more accurately determine which patients are more likely to benefit from surgery."

People who have experienced a stroke or a transient ischemic attack within the past four months are eligible for the study. Patients enrolled in the study will have a P.E.T. scan. If the P.E.T. scan is abnormal, one half of the participants will be randomly assigned to receive brain bypass surgery and the other half will receive medical therapy alone. Brain scans, surgery and all supplemental medical treatments are provided free of charge.

People interested in enrolling in the study should discuss their options with their personal physician.

University of Iowa Health Care describes the partnership between the UI Roy J. and Lucille A. Carver College of Medicine and UI Hospitals and Clinics and the patient care, medical education and research programs and services they provide. Visit UI Health Care online at

STORY SOURCE: Joint Office for Marketing and Communications, University of Iowa Health Care, 200 Hawkins Drive, Room E110 GH, Iowa City, Iowa 52242-1009

MEDIA CONTACT: Tom Moore, 319-356-3945, Pamela Jacobs or Marge Rogers, (319) 384-5824,