Health Essentials from Cleveland Clinic

Good blood flow throughout the body is important. That’s why stenosis, or narrow blood vessels, is a problem. Unfortunately, this problem can happen again. That’s when it becomes restenosis.

Balloon angioplasty and stent placement help restore blood flow through previously blocked arteries, but some patients develop restenosis (re-narrowing) over time.

Stephen Ellis, MD, Section Head of Invasive/Interventional Cardiology at Cleveland Clinic, explains, “There are effective ways to restore blood flow if restenosis occurs, but it’s important to assess the cause and to tailor treatment accordingly.”

Why does restenosis occur?

Despite advances, Dr. Ellis says, “in-stent restenosis still occurs in approximately 15 to 20 percent of patients within six to nine months, and sometimes afterwards. We have learned that restenosis is a very complex process.”

Some known causes include stents that are too small or misaligned in the blood vessel,  older-generation stents, or simply exuberant healing within the stent with scarring.

Test first to determine cause of restenosis

Before any treatment, your doctor will perform tests in order to understand what’s causing any problems. Catheterization allows doctors to look inside the artery and to perform tests including:

• Intravascular ultrasound that uses sound waves to see inside blood vessels
• Optical coherence tomography that uses light to create images

Tailoring treatment to the cause

Different options are available to treat restenosis the first time it happens:

1. Reopen the stented area.
   This is especially beneficial if the original stent turned out to be too small.Your doctor can do a repeat balloon angioplasty, which enlarges the opening of the blood vessel by pushing back plaque and scar tissue against blood vessel walls. Cutting balloon angioplasty uses tiny built-in blades that (once deployed) can cut out some of the plaque buildup. Both types of angioplasty are options for relatively short plaque blockages.
2. Use a better stent.
   Earlier generation stents (bare metal) stents can be replaced with newer drug-eluting stents.
3. Deliver medicine through balloon angioplasty.
   Balloon angioplasty itself can deliver a dose of scar-inhibiting medication. This treatment option avoids the placement of yet another stent. Studies are ongoing on this yet-to-be-approved technique.

Repeat problems

For some patients, restenosis is a recurring problem. If the blockage has recurred several times or if there are multiple blockages, your doctor may recommend bypass surgery to restore adequate blood flow.

Other options include:

Medicines. Two oral medications may lessen the risk of restenosis: sirolimus, the drug used on the first generation of drug-eluting stents, and cilostazol, another type of medicine that helps widen blood vessels and reduce clumping of red blood cells. These are typically used in conjunction with balloon or cutting balloon angioplasty.

Though useful, these drugs are not for every patient and they require more study, Dr. Ellis says.

Brachytherapy. This treatment uses radiation to keep scar tissue from building up again in the stent. Doctors perform brachytherapy at the same time as angioplasty.

After completing angioplasty, the doctor threads another catheter with a “ribbon” of radioactive particles (isotopes) to the blockage, leaves it in place for a few minutes, and then removes the catheter.

Brachytherapy is only performed at a few centers in the United States.

If you or someone you know has restenosis

When you face problems resulting from restenosis, it is important to find a center that has experienced doctors who are able to provide you with a broad range of treatment options.