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University of Iowa News Release

Aug. 22, 2003

Recent Findings Revise Treatment Of Un-ruptured Aneurysms

University of Iowa Health Care researchers are reporting that results from a major international study they helped conduct are providing important new information about the best way to treat people with aneurysms in the brain that have not yet ruptured.

Data from the International Study of Un-ruptured Intracranial Aneurysms (ISUIA) provided substantial new evidence showing that aneurysm size, location and a previous history of a ruptured aneurysm are the best predictors of future aneurysmal ruptures. The findings provide physicians with new insight regarding the risk-benefit of aneurysm repair versus conservative treatment, such as monitoring the aneurysm and observation of the patient.

An aneurysm is an area of weakness in a blood vessel, which usually enlarges over time. When a brain aneurysm ruptures, blood flows into the space surrounding the brain (the subarachnoid space), resulting in a subarachnoid hemorrhage (SAH), the deadliest form of stroke. SAH affects approximately 35,000 individuals each year in the United States. About 50 percent of patients with ruptured brain aneurysms will die within the first 30 days. Of those who survive, about half will suffer from severe neurological injury. It is estimated that up to 17 million people have or will develop un-ruptured aneurysms.

The ISUIA data showed that patients with multiple un-ruptured aneurysms and a previous history of rupture from a separate aneurysm were at greater risk for a second hemorrhage. Some of these individuals may benefit from interventional treatment of even smaller aneurysms depending on their location.

The researchers repaired the aneurysms with either a surgical or an endovascular approach. The surgical procedure, called neurosurgical clipping, involved performing a craniotomy (removing a section of the skull) and placing a surgical clip at the neck of the aneurysm. Endovascular treatment entails filling (occluding) the aneurysm with detachable platinum coils. The specialist inserts a catheter into an artery in the patient's leg and navigates it through the vascular system under X-ray guidance, into the head and into the aneurysm. Tiny platinum coils are then threaded through the catheter and deployed into the aneurysm, obstructing blood flow into the aneurysm in order to prevent rupture.

The study showed that disability and death rates following endovascular treatment were lower than those for surgery at both one month (9.1 percent endovascular versus 13.2 percent surgical) and one year (9.5 percent endovascular versus 12.2 percent surgical).

"Endovascular treatment such as 'coiling' resulted in less death and disability, despite the fact that the endovascular patient group was older and had more extenuating risk factors," explained John Chaloupka, M.D., UI professor and director of interventional neuroradiology at UI Hospitals and Clinics. "Further, since endovascular treatment is minimally invasive, patients typically experience less overall risk, less pain and shorter recovery times. These are very promising results."

The lifetime health care cost of caring for people with un-ruptured aneurysms in the brain in the United States is estimated at $522 million annually. When a SAH occurs, the lifetime health care costs of patients rise to approximately $1.8 billion each year, according to an article published in the New England Journal of Medicine.

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 Planning, Marketing and Communications, University of Iowa Health Care, 200 Hawkins Drive, Room 8798 JPP, Iowa City, Iowa 52242-1009.

CONTACT: Tom Moore, 319-356-3945,