Clogged blood vessels in the brain can be identified by computed tomography (CT) and opened by navigating a catheter into the blood vessel under X-ray fluoroscopy. But simultaneous real-time visualization of the brain and its vessels is not possible with either technique.
Now Columbia University Health Sciences and NewYork-Presbyterian Hospital researchers seek to replace X-ray fluoroscopy with endovascular magnetic resonance navigation to provide a better view of the brain and vessels for diagnosis and treatment of strokes. Magnetic resonance imaging (MRI) shows in real-time what tissue can be saved, what is dying, and the treatment being performed.
In January, General Electric Medical Systems awarded a $2.47 million, two-year grant to Columbia and NYPH to fund the collaborative research, led by Dr. John Pile-Spellman, professor of radiology, neurology, and neurological surgery at P&S and academic director of neurointerventional radiology. Columbia's Center for Advanced Information Management (CAT) also is providing funds to develop high-speed image acquisition protocols tailored to fit the requirements of interactive magnetic resonance fluoroscopy. Treatments for stroke typically involve inserting a metal-containing catheter in the groin and navigating it inside the body arteries to the brain vessels. But MRI machines contain powerful magnets that attract certain metals so the researchers have to develop magnetically neutral catheters and guide wires with new tags that appear in the MRI scans. The Columbia/NYPH researchers will study the new devices on pigs, which have blood vessels similar in size to those in the human brain.
"The grant came out of discussions with GE regarding what a great research university and academic hospital could do in the area of stroke if we think creatively about the future," says J. David Liss, vice president for government relations and strategic initiatives at NYPH. The hospital's patients will have first access to the technology, but GE subsequently will market it to other hospitals.
Dr. Pile-Spellman's collaborators include Dr. Robert DeLaPaz, professor of radiology; Dr. Joy Hirsch, professor of functional neuroradiology; Dr. Truman Brown, professor of radiology and the Percy & Vita Hudson Professor of Biomedical Engineering; Dr. Andrew Laine, associate professor of biomedical engineering and radiology; Dr. J. P. Mohr, Sciarra Professor of Neurology; Dr. Lei Feng, a postdoctoral fellow; and Dr. H. Christian Schumacher, a postdoctoral stroke research fellow and project manager for the research.
Before the 1990s, severe brain injuries leading to coma were widely considered untreatable. Then the "Decade of the Brain brought dramatic new therapeutic interventions for stroke, neurotrauma, seizures, and other serious neurological disorders, including improved scanning techniques; brain pressure monitoring, a method that measures oxygen levels in the brain; and regulated hypothermia, a technique that applies cooling to protect the brain during the first few days after trauma.
At the same time, physicians within neurosurgery, neurology, anesthesiology, and critical care medicine developed special expertise in the intensive care management of these conditions. But these physicians had not organized their efforts to establish a recognized subspecialty of medicine.
Now, Columbia Presbyterian Medical Center, one of the leading facilities for treatment of life-threatening neurological disorders, will serve as the home for the newly established Neurocritical Care Society, a non-profit organization whose mission is to bring together a diverse group of physicians from different specialties who treat neurological and neurosurgical patients in the critical care environment.
"We are excited about the possibilities the creation of a professional organization presents," says Dr. Stephan Mayer, associate professor of clinical neurology and neurosurgery and director of the Neurological Intensive Care Unit. "It is important for people to know and understand that there is often no reason to give up hope in an acute situation, such as a brain hemorrhage or a severe stroke. Because of this field, people are recovering from levels of brain injury and depths of coma that 10 years ago was unthinkable."
Dr. Mayer serves on the society's organizing committee and will act as associate editor of the society's official journal, Neurocritical Care, slated to be launched in January 2004. The society's inaugural meeting was held Feb. 15 and 16 during the 28th International Stroke Conference in Phoenix, Ariz. For more information, visit http://www.neurocriticalcare.org.
For years, doctors have promoted colorectal cancer screening. But physicians have debated the benefits and risks of colonoscopy (which examines the entire length of the colon and rectum) and sigmoidoscopy (which examines the rectum and the section of the colon closest to the rectum), partly because of the greater risk of perforation of the large bowel with colonoscopy.
Sigmoidoscopy was believed to have a much lower incidence of perforation than colonoscopy, but few studies have compared perforation rates for the two procedures directly. A new study from Columbia University Health Sciences researchers reviewed eight years of data comparing the two procedures.
To compare the perforation risk in people age 65 and older, Mailman School of Public Health graduate student Nicolle M. Gatto and Dr. Alfred I. Neugut, professor of medicine at Columbia's College of Physicians & Surgeons and professor of epidemiology at Mailman, and colleagues used a national database of people who had at least one colonoscopy or sigmoidoscopy between 1991 and 1998.
The researchers found the perforation rate in colonoscopies to be approximately twice the rate for sigmoidoscopies. Of 39,286 colonoscopies in the analysis, there were 77 perforations (1.96 perforations per 1,000 colonoscopies) compared with 31 perforations in 35,298 sigmoidoscopies (0.88 perforations per 1,000 sigmoidoscopies). The findings appeared in the Feb. 5 issue of the Journal of the National Cancer Institute.
But the difference in risk between the two procedures has been narrowing because the perforation risk from colonoscopy has decreased over the years, possibly because of improvements in technology and in the training of people performing the procedures. As the difference in perforation risk between the two procedures narrows, colonoscopy becomes more valuable as it offers more complete visualization of the colon than sigmoidoscopy.
The researchers expect the findings to help clinicians make better screening and diagnostic decisions for individual patients and to help policy officials create improved guidelines for colorectal screening programs. March is Colorectal Cancer Awareness Month.