Opening of Kidney Arteries Brings Dangers

(HealthDay News) -- Angioplasty and stenting can open blocked kidney arteries, but the procedure also throws off an immense amount of debris that can hurt kidney function, a new study shows.

It has been known that this procedure -- done primarily to relieve high blood pressure -- is messy, but "this is the first paper in humans to really demonstrate how much stuff there is and especially how much microscopic material there is," said Dr. Matthew Edwards, an assistant professor of surgery at Wake Forest University Baptist Medical Center and lead author of a report in the June issue of the Journal for Vascular Surgery.

Angioplasty and stenting for blocked kidney arteries involves the insertion of a balloon to open the artery, followed by the implantation of a tube to keep it open. The procedure doesn't get as much attention as a similar surgery done for heart vessels, but an estimated 40,000 to 80,000 Americans receive this intervention each year, Edwards said. The operation's primary purpose is to lower blood pressure caused by a blockage, and its ultimate goal is to prevent kidney failure, he said.

The new report described 28 angioplasty cases in which the physicians took blood samples after a stent was implanted.

Laboratory analysis revealed an average of 2,000 debris particles in the blood samples -- some pieces being big enough to block smaller vessels in the kidney.

The number of particles found in specific patients was directly related to their subsequent kidney function, the researchers found: more debris, worse kidney function.

That can bode ill for patient's longer term health, Edwards said, since "poor kidney function after kidney artery stenting has been previously demonstrated by our group to be associated with increased risk of heart attack, stroke or death in the future."

Post-angioplasty debris was also found to float freely in arteries, even though the surgeons used a protective device designed to trap it for removal. The Wake Forest surgeons used one of several protective devices now being tested. None have yet been approved by the U.S. Food and Drug Administration.

One or another of these protective devices may someday go into medical practice, Edwards said. "We certainly need a protection device," he said. His group used one designed by Medtronic. It is essentially a large balloon that traps the debris so that it can be collected and removed when the procedure is finished.

But Edwards also noted that certain kinds of fatty plaques could create more debris than others.
"The plaques that sit in these arteries are not all the same," he said. "Some might be prone to liberate more debris than others."

Edwards hopes that, in the future, this most dangerous form of debris could be identified before a procedure is done.

"There has been some work on that in the carotid artery," Edwards said, referring to the main artery to the brain. "Some MRI and ultrasound studies have identified plaque that is prone to release more debris."

Edwards said his group now is conducting a trial to explore that possibility.

More information
There's more on kidney angioplasty at the University of Southern California.

Mom's Antidepressant Use Poses Little Danger to Baby

(HealthDay News) -- Pregnant women who use antidepressants known as selective serotonin reuptake inhibitors (SSRIs) are not increasing the risk of most birth defects for their newborns, new research suggests.

Drugs within this class -- which include Celexa, Paxil, Prozac and Zoloft -- may increase the risk for certain defects, but, even then, the absolute risk is extremely small, concluded two studies published in the June 28 issue of the New England Journal of Medicine.

"It's a fairly reassuring message for women who need antidepressants and are pregnant or who plan on becoming pregnant," said Carol Louik, lead author of the first paper and an assistant professor of epidemiology at Boston University's Slone Epidemiology Center. "We saw no large risks, and the fewer elevated risks that we did see would only lead to very small absolute risks."

"This is a valuable contribution," added Dr. Jon Shaw, director of child and adolescent psychiatry at the University of Miami's Miller School of Medicine. "It substantiates the need to always be prudent in prescribing antidepressants."

The issue of maternal use of antidepressants, particularly those known as selective serotonin reuptake inhibitors (SSRIs) is a charged one.

Last November, the American College of Obstetricians and Gynecologists recommended that women avoid the SSRI Paxil if they are pregnant or planning on becoming pregnant, due to a potential heightened risk of birth defects.

The guidelines come a year after the U.S. Food and Drug Administration (FDA) issued a warning about possible birth defects associated with Paxil when the drug is taken during the first trimester of pregnancy.

The initial FDA warning came in September of 2005. In December of the same year, the FDA instructed Paxil's maker, GlaxoSmithKline, to reclassify the drug from a Category C to D (a stronger warning) for pregnant women. Category D means studies in pregnant women have demonstrated a risk to the fetus.

Other reports had indicated that SSRIs may cause newborns to have withdrawal symptoms.
To complicate matters further, yet another study found that pregnant women who discontinued their antidepressant medication were five times more likely to relapse into depression than women who continued with the medication.

Women of reproductive age have the highest prevalence of major depressive disorders, with experts estimating that about one in 10 will experience a bout of major or minor depression sometime during pregnancy or the postpartum period.

The first study, conducted by Louik's team of Boston researchers, looked at almost 10,000 infants with birth defects and close to 6,000 infants without birth defects. The researchers wanted to see if there was an association between defects that had been previously linked to SSRIs and the use of these drugs by mothers during their first trimester of pregnancy.

Overall, SSRI use was not associated with significantly increased risks of craniosynostosis (when connections between skull bones close prematurely), omphalocele (when intestines or other abdominal organs protrude from the navel) or heart defects.

There were, however, associations between maternal use of Zoloft (sertraline) and omphalocele and septal defects (defects in the walls that separate the chambers of the heart) and between Paxil and defects that interfere with blood flow to the lungs.

But even if a certain drug increased rates by a factor of four, the risk of having a child affected by the problem would still be less than 1 percent, the researchers said.

The study was funded by grants from the U.S. National Institute of Child Health and Human Development and the U.S. National Heart, Lung, and Blood Institute, as well as drug companies Aventis, Sanofi Pasteur and GlaxoSmithKline (maker of Paxil).

A second study, this time conducted by scientists at the U.S. Centers for Disease Control and Prevention (CDC), Atlanta, found that the use of SSRIs during the first trimester of pregnancy was not associated with any increased risks of most categories of birth defects, including congenital heart defects.

The researchers looked at four SSRIs: fluoxetine (Prozac), sertraline (Zoloft), Paxil and citalopram (Celexa).

There were some associations between maternal SSRI use and anencephaly (a brain defect), craniosynostosis and omphalocele, but, again, the absolute risk was very small. These defects had not previously been associated with SSRI use during pregnancy, the study authors noted.
Louik said she did not anticipate any labeling changes based on these studies, but that she did anticipate more research.

"These studies make a large contribution to the field, but they're not the final word by any means," she said.

More information
There's more on treating depression during pregnancy at the March of Dimes.

'Memory Traces' May Help Spur Chronic Pain

(HealthDay News) -- Even after their injuries have healed, some people continue to suffer chronic pain that can't be totally relieved through traditional analgesic drugs, such as aspirin and morphine derivatives.

Scientists have long tried to uncover the reasons for this kind of serious pain and to find effective treatments for it.

Now, a new study by a researcher at Northwestern University School of Medicine suggests that a main cause of this form of chronic pain may be old "memory traces" that get stuck in the brain's prefrontal cortex, which controls emotion and learning. As a result, the brain seems to remember the injury as if it were fresh, even long after it's healed.

Vania Apkarian, a professor of physiology and anesthesiology, says his findings from research with rats indicates there may be an abnormal cognitive memory and emotional component in the brain that causes the chronic pain.

He also identified a drug -- D-Cycloserine -- that controls persistent nerve pain by targeting the area of the brain that experiences the emotional suffering of pain. Over the past decade, the drug has been used to treat phobic behavior.

In rats, the drug appeared to greatly reduce pain-related emotional suffering and sensitivity of injury sites that had healed.

The next step will be to test the drug in clinical trials, Apkarian said.

The findings appear online in the journal Pain and will be published in print this fall.
The study was funded by the U.S. National Institutes of Health.

More information
The American Academy of Family Physicians has more about chronic pain.