People about to undergo a controversial stenting procedure in the neck might want to check their doctor's credentials first, researchers say.

According to a new study in the Journal of the American Medical Association, patients whose doctors do lots of the procedures are nearly half as likely to die over the next month as those in less-experienced hands.

During the treatment, called carotid stenting, doctors clean out cholesterol buildups in the carotid artery in the neck that sometimes cause strokes. Then they insert a small metal mesh tube, the stent, to prop the vessel open.

But if they're unfortunate, part of the cholesterol deposit might break off during the procedure and be released into the blood stream, producing the dreaded stroke the patient hoped to avoid.

"A little piece of it just flows upstream and can lodge in a smaller blood vessel in the brain," said Dr. Ethan A. Halm, who wrote an editorial about the new findings.

Based on Medicare records of nearly 25,000 procedures, the new study found a 30-day death rate of 1.4 percent in patients whose doctors placed at least 24 stents a year. By contrast, that death figure was as high as 2.5 percent when the doctors did six or fewer procedures annually.

The same pattern held true when comparing the initial and later procedures done by inexperienced doctors.
Dr. Brahmajee Nallamothu, a cardiologist at the University of Michigan in Ann Arbor who led the work, said the findings don't prove that lack of familiarity with the procedure explains the findings.

But he said that is likely to be the case, since there are no uniform standards for the training doctors need to undergo before they can perform carotid stenting.

"Patients shouldn't be shy about asking their physician who is going to be doing this procedure," Nallamothu told Reuters Health. "I think that it's a very fair question. If I were a patient, I would certainly want to know."

Halm added that carotid stenting is not the only alternative for patients with clogged arteries. The more common procedure is surgery, and some doctors recommend sticking just to medications. Especially when people have no symptoms, many believe doing surgery to clean them out is too hazardous.

With drugs alone, he told Reuters Health, the yearly stroke risk can be lowered to less than one percent, challenging the need for a procedure with significant risks.

And he added that the new study doesn't look at the total number of strokes caused by stenting, which tend to outnumber deaths by a factor of three.

"It's particularly important that people weigh the pros and cons of all therapies," said Halm.

In his view, the new results deal a blow to carotid stenting, which has become more and more common since it was approved in 2004. He estimated some 10,000 carotid stenting procedures were performed each year during the study, a number that has likely increased.

"There are a lot of tricky elements to the procedure," Halm said. "The article by Nallamothu shows that more people think they can do it well than actually can do it well."

If people decide that stenting is the right option for them, they might still have a hard time finding an experienced doctor to perform the procedure.

"The easiest piece of advice is to use an expert middle man," Halm said, adding that a neurologist can usually guide patients to an appropriate expert.

Nallamothu said he hoped the new study would spur the development of stricter training protocols and ensure that patients are followed more closely after stenting in the future.