New procedures, devices, guidelines
BY ADAR NOVAK
Physicians Develop New Transcatheter and Hybrid Cardiac Procedures
For some patients with aortic stenosis primarily the elderly and those already in fragile health standard aortic valve replacement surgery may be too risky since the procedure involves opening the patient’s chest, stopping the heart, and placing the patient on a bypass machine.
Using both surgical and catheter-based methods, P&S physicians are now exploring a new technique, called a transcatheter aortic valve replacement. This involves placing a tissue valve on a stent in a catheter that can be threaded into the femoral artery or the apex of the heart and replacing the valve without ever splitting the chest, stopping the heart, or using cardiopulmonary bypass. The new method is used on select patients in the PARTNER study, a Columbia-led, multi-center trial that includes the Cleveland Clinic, Emory University, and the University of Pennsylvania. Physicians eventually hope to involve at least 600 patients.
“Ten years from now I believe most aortic valve replacements will be done this way,” says Mathew Williams, M.D., assistant professor of surgery (in medicine) and surgical director of Cardiovascular Transcatheter Therapies at P&S. “This is a very exciting technology.”
Other hybrid approaches that involve both surgery and catheter procedures are increasingly being explored for possible use in treating a host of cardiac problems, Dr. Williams says. Like many minimally invasive approaches, hybrid techniques can be less painful for the patient, have shorter recovery times, and may be more effective.
Dr. Williams, a 1996 P&S graduate, also is bridging the gap between interventional cardiology and cardiac surgery; he is the only physician in the United States trained in both fields. “If a patient with coronary artery disease needs treatment, an interventional cardiologist may recommend a stent, and a cardiac surgeon may recommend bypass,” Dr. Williams says. “The advantage of being trained in both fields is that it makes you the most unbiased decision maker, having the knowledge base to know which one might be better and understanding the technical limitations of both procedures.”
Dr. Williams is involved in several clinical trials of hybrid procedures with CUMC colleagues Craig R. Smith, M.D., the Calvin F. Barber Professor of Surgery; Mehmet Oz, M.D., professor of surgery; Martin Leon, M.D., professor of medicine; Jeffrey Moses, M.D., professor of medicine; Susheel Kodali, M.D., assistant professor of clinical medicine, and others. They are working in a room in the catheterization laboratory that also functions as an operating room. Plans to build two more hybrid rooms are under way.
In addition to the PARTNER study, Dr. Williams and colleagues are involved in the Everest Trial, a clinical study to evaluate the percutaneous mitral valve repair system in the treatment of patients with severe mitral regurgitation. Other hybrid techniques being explored include combined minimally invasive valve surgery and coronary stenting, combined bypass surgery and coronary stenting, and endovascular repair of aortic aneurysms.
“This work requires a huge amount of collaboration, and Columbia has been great for this, since it has one of the best cardiac surgery and interventional cardiology divisions in the country,” Dr. Williams says. “I think the future will bring even more collaboration and a greater role for hybrid-trained specialists.”
Dr. Williams can be reached at 212-305-9320 and by e-mail at firstname.lastname@example.org.
Brain Tests for Preemies May Help Physicians Get Earlier Handle on Potential Problems
Electroencephalograms, used to detect problems in the brain’s electrical activity, can help diagnose health problems from seizure disorders and head injuries to sleep disorders. Now P&S researchers are exploring the use of high-density EEGs an inexpensive, non-invasive method to observe the brain function of premature infants. The device may shed light on why some premature infants eventually face such problems as cerebral palsy, autism, and attention deficit disorder and whether treatments for babies born prematurely or who have undergone difficult delivery are effective.
|A healthy full-term newborn in the well baby nursery at New York-Presbyterian Hospital has EEG data collected while asleep. The data will be used as a control in studies to detect problems in the brains of premature infants. The same apparatus is used for premature newborns.
Philip Grieve, Ph.D., assistant professor of clinical biomedical engineering in the Department of Pediatrics (neonatology division), is leading the effort and believes that research at Columbia in this area is unique.
“We’re trying to work backward earlier in a preemie’s life to see if we can get some help for the doctors who are treating the babies in the nursery,” Dr. Grieve says. “The brain is a very sensitive organ needing special protection. Doctors try to design therapies that support normal brain development while treating multiple problems in other organ systems. This EEG method may provide feedback about the treatments they are applying.”
The high-density EEG contains 128 sensors not the usual 16 to 25 that are easily placed over the infant’s scalp to monitor the electrical activity of the brain. These additional sensors offer doctors direct measurements of potentially at-risk regions of the brain, rather than relying on indirect measurements or more costly invasive tests such as MRIs.
Doctors tend to use MRIs only in the most devastating circumstances, Dr. Grieve says, so the two methods may complement each other and help confirm the results of the other test. Researchers who have conducted MRI measurements have seen differences in the brain anatomy of premature infants and have linked these differences to increased risk for poor outcome.
“This gives credence to the idea that you could also link EEG measurements to outcome,” Dr. Grieve says.
Dr. Grieve’s team has applied for NIH funding for studies that would allow them to relate EEG findings to risk factors in the development of premature infants. The researchers are expanding their pilot study to a larger group of premature and full-term infants; eventually they intend to correlate the EEG measurements made during hospitalization with results from outcome studies in which premature infants return to the hospital for follow-up testing and long-term tracking. They also are measuring the characteristics of EEG sleep state cycling to evaluate stress from labor and delivery, or problems in the early newborn period. The analysis of these EEG measures may enable researchers to learn which preemies will develop normally and which will have functional or developmental problems later in life.
Dr. Grieve can be contacted at 212-305-0953
New Developments in Brain Tumor Management
More research and innovation are under way in the field of brain tumor management than ever before, says Steven Rosenfeld, M.D., Ph.D., the John and Elizabeth Harris Professor of Neurology and director of the Neuro-Oncology Program of the Herbert Irving Comprehensive Cancer Center. Dr. Rosenfeld and his colleagues are at the forefront of clinical care and research.
One significant multi-center trial in which the Irving Center has participated involves the use of Avastin, a drug originally approved by the FDA for the treatment of colon cancer. “The effects have really been quite amazing in the treatment of patients with malignant gliomas, the most common malignant brain tumor in adults, and the most common kind treated at Columbia,” Dr. Rosenfeld says. Avastin, which is now being used clinically and in combination with other treatments, inhibits tumor growth by cutting off the tumor’s blood supply.
“We are very impressed with the effects of this drug and how it improves patients’ quality of life and length of life,” Dr. Rosenfeld says. He adds that CUMC, in partnership with the drug company Genentech, has become a regional leader in this therapy.
The center also has investigated the use of about a dozen signal transduction inhibitors such as Tarceva, Iressa, and Rapamycin a drug class that targets defects and mutations in biochemical communication within the cell. Some of the drugs are being used with gene expression profiling to fingerprint tumors; ultimately this may allow the development of drug therapies targeted specifically to an individual’s tumor. In addition, other P&S and multi-institutional trials in which Columbia is participating are exploring the use of anti-angiogenic compounds, targeted therapies utilizing a component of scorpion venom that can be used intravenously or injected into the tumor directly, and new methods of delivering drugs to circumvent the blood-brain barrier, such as ANG 005.
About 400 patients are seen by Columbia’s brain tumor specialists each year and the number continues to increase. Treatment and management of brain tumors do not stop at treating the tumor; the whole patient with the patient’s family is helped by the center’s unique psychosocial approach. Social workers, psychologists, and psychiatrists work with other medical specialists to tailor treatment to meet specific needs. The patient symptom management clinic, staffed by both social workers and nurses, also plays a key role. Twelve clinical trials are ongoing under Dr. Rosenfeld’s supervision.
“This is a momentous time to be working in this field,” Dr. Rosenfeld says. “And it is a great advantage to be doing this work at the Herbert Irving Comprehensive Cancer Center, where world-class experts are working together to deliver the most innovative therapies to patients with brain tumors.”
The Irving Center online: hiccc.columbia.edu
Dr. Rosenfeld and the Division of Neuro-Oncology can be contacted at 212-305-1718.
|A Wide Range of Care
At Columbia, patients with brain tumors are offered a broad spectrum of care from world-class specialists in such modalities as computer-based stereotaxis, neuroendoscopy, awake brain mapping, and electrophysiological mapping.
Jeffrey Bruce, M.D., the Edgar M. Housepian Professor of Neurological Surgery, director of the Bartoli Brain Tumor Research Laboratory, and co-director of the Brain Tumor Center, specializes in treating tumors of the pineal region of the brain.
Neil Feldstein, M.D., associate professor of neurological surgery, is director of pediatric neurological surgery.
Guy M. McKhann II, M.D., the Florence Irving Associate Professor of Neurological Surgery, treats patients suffering from epilepsy.
Michael Sisti, M.D., the James G. McMurtry Associate Professor of Clinical Neurosurgery, Radiation Oncology & Otolaryngology, is co-director of the Center for Radiosurgery.