Medical Device Daily Washington Editor

Translational medicine is a big point of emphasis in modern healthcare, but the experience a surgeon has with some procedures is often crucial to outcomes. All the same, a recent study indicates that with the proper training, surgeons with little experience in carotid artery stenting can achieve results that are comparable to those attained by their more experienced brethren.

In a study that will be published in the January 2007 edition of the Journal of the Society for Cardiovascular Angiography and Interventions, researchers at the Columbia University Medical Center (New York) polled the results of roughly 3,500 carotid artery stenting procedures from more than 140 hospitals across the U.S. The 353 physicians whose work was evaluated ranged in experience from beginners with the appropriate training and mentoring to the surgeons who helped pioneer the procedure.

The stenting device, the Rx Acculink, cleared the FDA in 2004 and joined the suite of products offered by Guidant (Indianapolis) prior to the buyout by Boston Scientific (Natick, Massachusetts). The so-called CAPTURE registry tracked rates of death, heart attack and stroke, which showed up at non-significant differences between the three groups of surgeons at 5.3% for the most experienced group, 6% for those with a “moderate” level of experience, and 7.4% for surgeons with little experience with the procedure.

One of the strengths of the study was that a group of independent reviewers reviewed the data on the surgical outcomes, a point of independence that earns raves at federal agencies. Christopher White, MD, editor-in-chief of the journal, said that because of that feature, “we can have confidence that the data are robust, meaningful and applicable to community practices.” The patients all went through a neurological exam just prior to the procedure, then a second exam a day later. The final follow-up for the purposes of the study took place 30 days after the operation.

The procedure calls for insertion of the Rx Acculink and an associated filter into the femoral artery, which the surgeon then steers up through the aorta and into the carotid. Between the urgency of the condition and the difficulty of guiding the stent and filter over that long a distance, this is one of the more delicate procedures in cardiovascular surgery, and training is vital to ensure solid outcomes.

William Gray, MD, an associate professor of medicine and the director of endovascular services at Columbia said that the CAPTURE review “is a giant step toward achieving the goal of proving that in the foreseeable future, nonsurgical carotid stent placement will replace surgery as the treatment of choice for stroke prevention.”

Diagnostics for Alzheimer’s picking up steam

Despite the difficulty that X-rays have penetrating the skull, imaging technology continues to prove itself a vital resource for physicians, especially when attempting to provide an early diagnosis of neurological disease. Researchers at the University of California at Los Angeles (UCLA) have established that a relatively new diagnostic agent does indeed offer more accurate diagnoses than previous generations of radio-labeled diagnostics.

In a study of 83 volunteers, a team at UCLA found that FDDNP, a large-molecule isotope that binds to two types of abnormal tissue in the brain, used with positron-emission tomography (PET) more accurately predicted Alzheimer’s than magnetic resonance or PET scans using FDG (fluorodeoxyglucose) as a radio-labeled dye. The research, which appeared in an article in the Dec. 21 edition of the New England Journal of Medicine, showed that of the 83 volunteers, 25 had early-stage Alzheimer’s, 28 had some sort of low-grade cognitive impairment, and the balance of 30 scanned clean. FDDNP was initially more accurate than the other two scanning technologies and maintained the lead after two years.

Richard Hodges, MD, the director of the National Institute on Aging (NIA) at the National Institutes of Health, said that the current number of Americans who suffer from Alzheimer’s, which stands at about 4.5 million, could triple by mid-century. He remarked that medical science “urgently needs techniques to see brain changes in the earliest stages of cognitive decline so that we can identify people at risk and test drugs to slow or stop the progression.”

FDDNP attaches to a pair of pathological tissues in the brain, namely neurofibrillary tangles and beta amyloid plaques in the hippocampus, which actually is two organs, one on each side of the brain. As an important element in the limbic system, the hippocampi, as they are known to scientists, can severely derange normal cognitive and affective function. Other elements of the limbic system include the amygdale, which regulates aggressive behavior, and the hypothalamus, which pairs with the pituitary to control a wide range of metabolic and somatic functions.

NIA, which was a major contributor to the funding of the study, is also involved in the Alzheimer’s disease Neuroimaging Initiative, which is currently pairing PET scanning with another radioactive dye, Pittsburgh Compound B, to detect early-stage Alzheimer’s. The initiative coordinates a number of public/private efforts to diagnose and treat Alzheimer’s disease and lists a number of clinical trials at its web site.

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