Computer-controlled magnetic fields navigate instrument within blood vessels of human brain

St. Louis 16 April 2001Washington University physicians at Barnes-Jewish Hospital in St. Louis completed the first use of a Magnetic Navigation System designed to use computer-controlled magnetic fields to steer an instrument within the blood vessels of the brain to reach an aneurysm, an abnormal blood-filled dilation of a blood vessel. Two procedures were successfully completed on a 55-year-old man and a 64-year-old woman by Dr. Christopher J. Moran. Although clinicians regularly navigate instruments, typically catheters or guidewires, manually to the brain through the femoral artery for the repair of aneurysms, this is the first time the instrument has been steered utilising computer-controlled magnetic fields.


The system, approved for use in clinical trials by the U.S. Food and Drug Administration (FDA) under an Investigational Device Exemption (IDE), is being tested as a new way to navigate devices within the brain and the heart. The system was developed by Stereotaxis Inc., a St. Louis-based company in the field of interventional robotics. The technology integrates a magnetic field actuator with image guidance techniques and computer control to create an interventional workstation, with the potential to provide remote digital navigation of catheter-based therapeutic or diagnostic devices along complex trajectories within the body.

"The field of interventional medicine is being revolutionised through computer integration in the cath lab, and Stereotaxis is at the forefront of the technology", stated Bevil J. Hogg, president and chief executive officer of Stereotaxis. "The medical community has a growing need for more efficient, cost-effective and, above all, less invasive interventional procedures. Our new system has the potential to fulfil that need through the use of digitally controlled catheters. In providing programmatic control of catheters and other interventional devices, Stereotaxis expects to play a key role in the rapidly increasing computerisation of the catheterisation laboratory."

Dr. Moran, an associate professor of radiology at Washington University School of Medicine, is the principal investigator who, along with several other interventional neuroradiologists, is leading the clinical trial at Barnes-Jewish Hospital. "Reaching the site of a brain aneurysm has always been a difficult procedure, but this new technology has the potential to improve the way we can gain access to sites in the brain during a procedure within the vascular system", stated Dr. Moran. "This new system addresses the challenges we face with this type of procedure. For the first time, we used a computer to help us steer the instrument through the blood vessels to the brain."

According to Dr. Moran, clinicians currently must manually navigate devices from the femoral artery to the brain. With the Magnetic Navigation System, under the direction of the physician, the computer is designed to steer the instrument, directly at the distal tip, to various vessels supplying the brain in order to access the site of the aneurysm. "Globally, there are about 80.000 aneurysm patients discovered each year. An untreated, ruptured aneurysm may result in death", Dr. Moran stated. "Therefore, it's critical that we have a means of accurately and quickly locating and treating the source of the bleeding."

The study also encompasses using the catheter to navigate to sites for the subsequent treatment of stroke, arterial venous malformations, and other embolisation procedures. Thirty patients will participate in the clinical trial in St. Louis. Testing is expected to be complete in 2001. This is the third clinical trial for the Magnetic Navigation System. The second trial began in January at Washington University School of Medicine using a magnetically controlled catheter to navigate within the heart to discover the source of cardiac arrhythmias. The cardiac trial is nearly halfway complete. The first trial in 1998 involved using a magnetically-guided biopsy device in neuro-surgery.

Stereotaxis was founded in 1990 to further develop the pioneering work in magnetic instrument guidance by several researchers at the University of Virginia, University of Iowa, and the University of Washington. The company is funded by a number of prominent venture capital firms. Washington University School of Medicine in St. Louis is considered one of the top five medical schools in the country, known for providing excellence in medical research, teaching, and patient care. The school receives more than $300 million a year in grants and contracts to support its research efforts, which ultimately are geared toward finding treatments and cures for devastating diseases. The medical school faculty are the physicians and surgeons who provide cutting-edge medical care to the patients of Barnes-Jewish and St. Louis Children's Hospitals.

Leslie Versweyveld

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