Angioplasty procedure can impair kidney function

Washington -- A new study has found that angioplasty, the most common procedure for clearing blocked kidney arteries, has potential to damage kidneys.

Researchers at Wake Forest University Baptist Medical Center found that it does so by releasing release thousands of tiny particles that can impair kidney function into the bloodstream.

Based on laboratory studies, researchers have suspected that angioplasty releases particles into the bloodstream – presumably made up of bits of clot and fatty plaque material from the blockage.

The goal of the current study was to count the particles and determine if they are associated with impaired kidney function after the procedure.

In 28 angioplasty cases, researchers used a protection device to temporarily block the vessel at the site of the angioplasty and stenting. After the procedure, and while the protection system was still in place, researchers took a small sample of blood trapped by the protection device. The arterydefine was then aspirated and flushed out to remove any remaining particles.

Laboratory analyses found a mean of 2,000 particles captured per blood sample – many of them large enough to block the small vessels in the kidney.

“The more particles collected from a patient, the worse their kidney function. Patients with higher levels of particles in their blood were more likely to have decreased kidney function after the procedure. 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,” said Matthew Edwards, M.D., M.S., lead researcher and an assistant professor of surgery.

Researchers now suggest that having patients stop aspirin use before the procedure may lead to worse results. It also shows that stent size is important and raises questions about whether blocking or filtering out the debris, known as emboli, may be effective in improving results.

“This is the first data in humans to show that debris released during angioplasty and stenting of the kidney arteries can be harmful to kidney function. It raises important questions about how to most safely perform this very common procedure,” said Edwards.

“New devices exist that may prevent the passage of this debris into the kidney and may lead to better patient outcomes. We are currently conducting a clinical trial to explore this question,” he added.

The results raise an important question: since the protection device was in place for the procedures, and it is designed to remove particles from the vessel, why did patients who had high particle counts before the artery was flushed also have worse kidney function afterwards.

The researchers theorize that some blockages are more prone to releasing particles than others and that just putting the protection device in place releases particles that reach the kidneys.

“The study raises many questions, including how well the protection device works and can we predict which plaques are more prone to release debris,” said Edwards. “We are currently conducting a clinical trial to try and answer these questions.”

The new study, funded by the National Institutes of Health, will compare results in procedures performed with and without a protection device.

The study appears in the current issue of the Journal for Vasculardefine Surgery. (ANI)