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How Stents Save Lives

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By 6 a.m., the cath lab at Lankenau Medi-cal Center hums with activity. Rhythmic beeps sound and colors flash across monitors displaying vital signs as nurses and doctors hold hushed conversations with patients and their loved ones.

The calm, almost cheerful vibe belies the seriousness of the situation. Blockages of varying degrees are restricting blood flow in these patients’ hearts, putting their lives in danger. But they’re actually the lucky ones. Their symptoms led them to doctors’ offices before they suffered heart attacks. Via a procedure called coronary artery catheterization, their lives will be saved by a guide wire, a balloon, and a tiny metal device. Lankenau’s interventional cardiology team performs more than 2,000 of them a year.

Almost a half-million Americans get stents every year. It’s quite common among those over 65, when blockages result from aging and the accumulation of cholesterol in the arteries. Stents

are so common that a 2013 report from the American Medical Association and the Joint Commission questioned whether they were being used unnecessarily. But interventional cardiologists do believe stents save lives. And their technological evolution makes them vastly more effective than any alternative procedure.

Balloon angioplasties were the norm during the first half of Dr. Ancil Jones’ career. “In the ’80s through early ’90s, [it] was the only way,” says Crozer-Keystone Health System’s chief of cardiology.

The balloon was mounted on a catheter and threaded through the groin’sfemoral artery to the heart. Once in the coronary artery, it was inflated, pushing away the blockage and restoring blood flow to the heart. “But the balloon was somewhat unpredictable,” Jones says. “You couldn’t be entirely sure you’d get a nice, open artery.”

And it occasionally failed. “You could go from 80-percent blockage to 100-percent blockage,” he says. “Or there could be a dissection, which is when the balloon tears the vessel. Even a small tear in the lining of the artery could cause a scar to form, and that would also block the artery.”

Approved for wide usage in 1993, stents are stainless-steel, mesh-like devices that compress to fit onto catheters, which are also fitted with balloons. Via catheters, stents are placed near the coronary artery blockage. Physicians then inflate the balloon to disperse the blockage and open the stent, stretching it so it embeds intothe walls of the blood vessel. The balloon is then deflated and removed, but the stent stays.

Still, the procedure sometimes resultedin complications. In about 20 percent of patients, scar tissue grew, and the procedure would have to be redone. By 2003, there was a new variety of stent, coated with a medication that’s absorbed into the tissue of the blood vessel where it’sembedded. “That disallows cells from multiplying and forming scar tissue—or limits its thickness,” says Dr. Timothy Shapiro, director of Lankenau’s cardiac catheter lab. “Now, we only have to redo stents 5 percent of the time.”

Today’s stents are made of chromium, platinum and cobalt alloys. “[That] makes them thinner,” Jones says. “They’re also more visible on X-rays, so we can see exactly where they are.”

Even though they’re thinner, the new stents are stronger and more flexible than their predecessors. As previously mentioned, cardiologists traditionally used the femoral artery as the point of entry. Patients had to stay in the hospital overnight, lying flat to avoid bleeding and other problems.

These days, cardiologists typically go with the radial artery approach, going through the wrist rather than the groin. Recovery time is just a few hours.

What’s more, protocols for treating blockages have been vastly improved. It used to be that EMTs transported patients to hospitals, heart attacks were confirmed there, and procedures began. Now, EMTs are equipped with mobile EKGs. Results are electronically transmitted to the hospital.

“The EKG also gives us a good idea of where the blockage is and where we should go with the stent,” says Shapiro. “We almost always resolve the situation in less than 60 minutes, and we now have a survival rate in the 95-percent range. We have so few complications that we don’t expect patients to come back at all.”


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How manyartery-clearingprocedureshappen a year?Source: Centers for DiseaseControl and Prevention

2.4millionArteriographiesand angio-cardiographies using dye

​1millionCardiaccatheterizations

500,000Balloonangioplasties of the coronary artery

​454,000Insertions ofa coronaryartery stent

​395,000Coronaryartery bypass grafts