European trials call stenting risky, contradict US study

A controversy in the medical field popped up on Wednesday when two large European studies reported that stenting, a treatment used to prop open the critical blood vessel, carries a higher risk of stroke and death than a surgery.

Stenting is a procedure in which a cylindrical device, stent, is inserted into a hollow tubular organ, such as blood vessel, to provide artificial support and maintain the patency of the opening.

According to the French researchers, headed by Dr. Jean-Louis Mas of the Sainte-Anne Hospitals in Paris, going through the major operation to prevent strokes by opening up a neck artery and clearing out blockages is safer than the minimally invasive procedure in which surgeons implant a stainless-steel coil to prop open the critical blood vessel.

In their clinical study, sponsored by the French Ministry of Health, the French researchers studied 527 patients with blockage of internal carotid arteries greater than 60 percent and symptoms of stroke or transient ischemic attacks (TIAs). Internal carotid arteries are the major blood vessels that provide nutrition to the brain.

Researchers assigned 262 patients to stenting and other 265 patients to endarterectomy, a surgical procedure to remove the atheromatous plaque material. After studying them for six months they found that 11.7% of the patients who received a stent had either suffered a stroke or died, compared with 6.1% of those who underwent an endarterectomy.

A larger German study, reported in the medical journal Lancet earlier this month, also discovered a smaller, but statistically important, increased risk related with the stents and also called for a halt to their use.

The German study, which was sponsored by several government and private agencies, and the companies that produce the stents, included 1,183 patients who were also suffering from the symptoms from their blockage. After merely one month of observation, the researchers, headed by Dr. Werner Hacke of the University of Heidelberg noticed that 6.51% of those receiving a sent suffered a stroke, compared with 5.14% of those receiving an endarterectomy.

However, some American researchers are not agreeing with the European findings. According to them, the findings are in conflict with U.S. studies that indicated that the stents are safer than surgery.

A 2004 U.S. study, SAPPHIRE (Stenting and Angioplasty with Protection in Patients at High Risk for Endarterectomy), of 334 patients had found that 20.1% of those receiving surgical procedures to remove the blockage had a stroke or a heart attack or died in the year after surgery, compared with 12.2% of those receiving stent implantations.

Expressing his views on the European researches, Dr. Spencer King of the Fuqua Heart Center in Atlanta and a past president of the American College of Cardiology said, these results "are surprising given that the death and stroke rate after stenting seems higher than in previous U.S. studies."

An estimated 700,000 Americans suffer strokes each year, and many are caused by the buildup of plaque in the carotid arteries. New stents designed for use in carotid arteries were approved by the US Food and Drug Administration (FDA), two year sago. Just like the larger stents are used in coronary arteries to prevent heart attacks, the new stents compress the blockage and hold the artery open.

Disagreed with the French study, Gary Roubin, director of interventional cardiology at Lenox Hill Hospital in New York, said the French study differs in several aspects from the way stenting is performed in US. He said only about half the French patients received what would be considered appropriate medical treatment in America. In the US continent, patients are given two types of anti-stroke medicine when undergoing the procedure, Roubin said.

He concluded that as the French trial was stopped and then started again with the use of protection devices that most of the surgeons were still learning how to use, there may have been greater complications in the stent users. “For these reason I don’t believe this trial will impact practice in the (United States),” Roubin said.