More deaths when green doctors place neck stents
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.
What is carotid artery stenting?
Carotid artery stenting is a procedure in which your vascular surgeon inserts a slender, metal-mesh tube, called a stent, which expands inside your carotid artery to increase blood flow in areas blocked by plaque.
Hardening of the arteries, also known as atherosclerosis, can cause a build-up of plaque. In hardening of the arteries, plaque builds up in the walls of your arteries as you age. Cholesterol, calcium, and fibrous tissue make up the plaque. As more plaque accumulates, your arteries can narrow and stiffen. Eventually, enough plaque may build up to reduce blood flow through your arteries, or cause blood clots or pieces of plaque to break free and to block the arteries in the brain beyond the plaque.
“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.
How long has the carotid stenting procedure been performed?
The stenting procedure has been performed in clinical trials at Cleveland Clinic since the procedure was introduced in 1994 as an investigational treatment for carotid artery disease.
In 2004, the carotid stenting procedure was approved by the FDA as a treatment option for select patients who have carotid artery stenosis and meet certain criteria. The procedure is approved for patients who are experiencing symptoms, have a carotid artery that is blocked 70 percent or more, and for whom surgery would be highly risky.
Research is still ongoing to compare the results of the carotid stenting procedure with that of the carotid endarterectomy surgery. Most recently, a large randomized trial called the CREST trial compared the two treatment options and found that there were no significant differences in major risks of the two treatments.
Reference: Brott TG, Hobson RW 2nd, Howard G, Roubin GS, Clark WM, Brooks W, Mackey A, Hill MD, Leimgruber PP, Sheffet AJ, Howard VJ, Moore WS, Voeks JH, Hopkins LN, Cutlip DE, Cohen DJ, Popma JJ, Ferguson RD, Cohen SN, Blackshear JL, Silver FL, Mohr JP, Lal BK, Meschia JF; CREST Investigators. Stenting versus endarterectomy for treatment of carotid-artery stenosis. New England Journal of Medicine 2010 Jul1;363(1):11-23.
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.
###
SOURCE: Journal of the American Medical Association, September 27, 2011.
###
1. Brahmajee K. Nallamothu, MD, MPH;
2. Hitinder S. Gurm, MD;
3. Henry H. Ting, MD;
4. Philip P. Goodney, MD;
5. Mary A. M. Rogers, PhD;
6. Jeptha P. Curtis, MD;
7. Justin B. Dimick, MD;
8. Eric R. Bates, MD;
9. Harlan M. Krumholz, MD, SM;
10. John D. Birkmeyer, MD