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Release: Oct. 25, 2002

Research results show new technique for treating brain aneurysms is superior to surgery

Results of a study in the Oct. 26 issue of The Lancet show that researchers -- including a member of a University of Iowa Health Care team -- have determined that a new approach to treating ruptured aneurysms in the brain is superior to surgery.

Researchers at 44 medical centers in Australia, Europe and North America participated in the International Subarachnoid Aneurysm Trial (ISAT). The study's investigators ended the trial early because the early results definitively showed that the new technique achieved better outcomes for patients than traditional surgery.

A brain aneurysm is an abnormal bulging outward of the wall of an artery. The defect is most common among people between ages 35 and 60. Brain aneurysms can cause a stroke when they rupture and blood flows into the brain or the space closely surrounding the brain.

The traditional treatment for a ruptured brain aneurysm was surgery. Neurosurgeons placed metal clips across the neck of the aneurysm in an effort to stop arterial blood from escaping into the brain.

In contrast to surgery, a less-invasive approach uses a technique called endovascular treatment. An interventional neuroradiologist inserts a small plastic tube called a catheter through an incision in the patient's leg into the femoral artery. The interventional neuroradiologist then uses X-ray guidance to navigate the catheter through the vascular system into the brain and inside the aneurysm. Next, the interventional neuroradiologist threads tiny platinum coils through the catheter into the aneurysm, obstructing the blood flow into the aneurysm.

Researchers say that the ISAT results indicate that treating ruptured brain aneurysms with coils – called embolization - results in better outcomes for patients when compared to the surgical placement of clips.

John C. Chaloupka, M.D., University of Iowa professor of radiology and director of the Interventional Neuroradiology Service at UI Hospitals and Clinics, is an internationally recognized expert in the endovascular treatment of brain aneurysms. He has served in various advisory and scientific capacities for several endovascular clinical trials, including a recently proposed international clinical trial comparing the outcomes of clipping versus coiling of unruptured aneurysms called the International Study of Unruptured Intracranial Aneurysms (ISUIA).

"The ISAT results provide a very important, albeit preliminary step, in changing the basic management paradigms of intracranial aneurysms, which will eventually transition endovascular techniques into a first line or primary treatment modality," Chaloupka said.

Chaloupka is one of the first physicians in the world to deploy micro-coils in brain aneurysms. Specialists at the UCLA Medical Center developed the technique from 1990 to 1991. For more than a decade, Chaloupka has performed several hundred micro-coil embolization procedures. Currently, UI Health Care specialists led by Chaloupka perform between 100 and 120 micro-coil embolizations to treat brain aneurysms each year, making UI Hospitals and Clinics one of the nation's leading centers for such procedures.

Investigators ended the ISAT study early when a planned analysis of the early results showed that the data about the endovascular technique's superiority were so convincing that to have continued enrolling patients would have been considered unethical.

Seon-Kyu Lee, M.D., currently a UI assistant professor of radiology, participated in ISAT while he was at the University of Toronto. "Although we will need to see the long-term outcome analysis of ISAT, the early-outcome results of this study will now provide a nice opportunity for neurosurgeons and neurointerventional radiologists to discuss evolving the management strategies for ruptured intracranial aneurysms," Lee said.

A stroke occurs every 53 seconds in the United States, affecting nearly 600,000 Americans. One third of them will die as a result, making stroke the nation's third leading cause of death, as well as the leading cause of severe, long-term disability. Bleeding into the brain causes about two out every 10 strokes. The other eight out of 10 strokes involve blockages in arteries that supply blood to the brain.

University of Iowa Health Care describes the partnership between the University of Iowa 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