Increasing circulation Weakened arteries given new life with steel mesh tube

October 23, 1990|By Sue Miller | Sue Miller,Evening Sun Staff

Don Jenkins, a disabled War II veteran, says the area aroun his groin has so many small scars that it "looks like a crossword puzzle."

The permanent marks are not due to an old wartime injury, but to catheters and other instruments used to enter his body for the 12 procedures he has undergone for a recurring problem -- blood vessel blockages.

Over the past decade, artificial arteries have been placed in both of his legs and he's had repeat bypass surgeries, using synthetic arteries to detour the circulation around the blockages. Laser treatment and balloon angioplasty also have been used to get rid of plaque buildup that clogs arteries.

He underwent treatment at Johns Hopkins Hospital, the University of Maryland Medical Center, the Harbor Hospital Center, St. Agnes Hospital and Union Memorial Hospital -- all without lasting success.

Then, five months ago, Dr. Frank J. Criado, a vascular surgeon at Union Memorial Hospital, implanted an experimental, balloon-expandable stent -- a delicate steel mesh tube -- inside -- an artery in the left side of Jenkins' abdomen. It is called the iliac artery.

The stent acts as a scaffold inside arteries to prevent their collapse and prolong the effectiveness of balloon angioplasty, which Jenkins' body had repeatedly rejected in the past.

By the time the stent was implanted, 95 percent of the circulation in Jenkins' right leg had shut down. And, the blood flow in his left leg was being newly threatened by a blockage in the iliac artery.

Balloon angioplasty had opened the artery briefly, but within two weeks it had closed down almost completely. Just a trickle of blood was getting through to his leg.

"I couldn't even walk up and down my front steps," said Jenkins, a Riviera Beach resident who operates his own insurance agency.

"But, I'll tell you how good the stent has been for me. I'm the color sergeant for the Maryland Defense Force in Glen Burnie, and I've been parading around a lot lately. The stent is working wonderfully. And, I'm so grateful for what the Union Memorial specialists did."

Since then, Criado has implanted a total of 10 stents in the iliac artery as an adjunct to balloon angioplasty and he hopes to do up to 100 in clinical trials at Union Memorial.

The procedure is undergoing trials in about 15 medical centers throughout the country. Results to date with 300 cases, involving the iliac artery, are "extraordinarily good," according to Criado, who heads the Maryland Vascular Institute at Union Memorial.

"The success rate, long term, has been 95 percent, and that's better than anything we have ever seen with angioplasty," said Criado, who recently was approved by the U.S. Food and Drug Administration to become the first clinical investigator in Maryland for the Palmaz iliac stent.

The stent was developed by Dr. Julio Palmaz, a vascular radiologist at the University of Texas Health Sciences Center in San Antonio.

The stent-angioplasty procedure takes between 45 and 90 minutes. Medication is given to minimize the discomfort a patient feels only when catheters are inserted in the groin area.

First, a balloon-tipped angioplasty catheter winds its way to the site of the blockage. The balloon is then inflated so it can squash the plaque buildup to the sides of the artery. The catheter is then withdrawn.

Plaque is caused by arteriosclerosis, or hardening of the arteries.

The stent -- which is very small, about one-third of an inch high and one inch long, and very thin -- is carried into the artery on a second balloon-tipped catheter to the site that had been blocked. As the balloon is inflated, the stent expands and becomes embedded in the inner layer of the artery where it remains permanently. The balloon is deflated and the catheter is pulled out.

Stent patients remain in the hospital overnight. Afterward, they are able to resume a normal life. They do not have to be on blood thinners but, like all balloon angioplasty patients, they are kept on aspirin permanently.

"We hope the aspirin will decrease the chance of artery reclosure and protect against heart attack because most of these patients have been shown to have heart disease," Criado said.

Patients who undergo the stent procedure for the iliac artery suffer from pain and cramping of leg muscles and have difficulty walking. Sometimes, their problem can be more severe, like gangrene in the toes.

"We feel the stent -- used in combination with balloon angioplasty -- is an important development because it addresses blockages of the iliac artery, which are very common and tend to be rather serious," Criado said.

"The alternative to angioplasty, when it cannot be done or is not successful, is major bypass surgery, which entails high costs and many risks. So, it is tremendously advantageous to avoid that and do a minimally invasive procedure."

Criado estimates the cost of the stent-balloon angioplasty procedure, after it is approved by the FDA, will be about one third of the $10,000 to $12,000 cost of bypass surgery for the iliac artery.

In the future, stents will be used not only in the iliac arteries, but in many other arteries, including the femoral arteries in the leg, the kidney arteries and the coronary arteries, he said.

In a recent study at Boston's Beth Israel Hospital, 37 patients were given balloon-expandable intracoronary stents to hold the artery open. Of these patients, 95 percent showed significant improvement. And, according to doctors involved in the procedure there, patients treated with stents have less than half the chance of having the artery re-narrow in six months than patients without stents.

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