Stroke treatment: Carotid and intracranial stents

If you've had a stroke, or have severe atherosclerosis in the brain arteries, carotid or intracranial stents may be an option for you.

Atherosclerosis, a buildup of fat and other substances (called plaques), causes hardening and narrowing of the arteries throughout the body. When enough plaques build up or a blood clot develops, the artery can become blocked. Depending on where the blockage occurs, it can cause serious consequences including heart attack and stroke.

When the blood supply to your brain is blocked, the blockage can cause a stroke. Strokes due to blockages of blood vessels can occur in two main areas: in the carotid artery in the neck — the carotid artery is the main artery supplying blood to the brain — or in an artery within the skull, called an intracranial artery.

Stroke treatment or stroke prevention depends on where the blood vessel blockage or narrowing occurs. Stroke treatment or prevention can include treating blocked or narrowed arteries with medicine or removing the buildup of plaques with surgery (such as carotid endarterectomy). But these stroke treatment and stroke prevention options aren't for everyone. For some, medication isn't effective; for others, surgery is too risky because of the location of the plaques or other health issues.

For atherosclerosis blocking the carotid arteries, angioplasty, a procedure to widen a blocked artery along with stenting, may be appropriate. Stents are small wire mesh coils that prop open the artery to improve blood flow. Angioplasty and stenting of carotid arteries may be an appropriate stroke treatment or stroke prevention option for some people who've had a stroke or transient ischemic attack (TIA, or ministroke) but can't undergo surgery. Stenting may also be an option for some narrowed intracranial arteries.

Carotid angioplasty and stenting

Your carotid arteries are located on each side of your neck and are the main arteries supplying blood to your brain. They're particularly important because they carry blood to the cerebral cortex, which is responsible for most of your day-to-day functioning. When atherosclerosis affects these vessels, it's called carotid artery disease. It's the equivalent of coronary artery disease — atherosclerosis affecting the heart arteries — just the location of the disease is different.

Many people with carotid artery disease take medications such as aspirin, blood thinners and cholesterol-lowering drugs to keep atherosclerosis under control, and to prevent heart attack and stroke. But for some people, medications aren't enough. When an artery becomes significantly blocked — usually 70 percent blocked or more — surgery may be recommended. The most common surgery for carotid artery disease is called carotid endarterectomy, when atherosclerotic plaques are surgically removed from the carotid artery in the neck. However, a newer, less invasive procedure — carotid angioplasty and stenting — can be used in certain cases.

What is carotid angioplasty and stenting?
Angioplasty and stenting are commonly used to widen narrowed heart arteries for treatment of coronary artery disease. Carotid angioplasty and stenting work similarly, but their long-term effectiveness has not yet been determined.

During the procedure, a long, hollow tube called a catheter is inserted in an artery in your groin, and then threaded through the arteries. When it reaches the narrowed carotid artery, the doctor inflates a tiny balloon at the end of the catheter to flatten the fatty deposits against the artery wall. Then, a wire mesh stent is deployed to keep the artery propped open and prevent re-narrowing.

Carotid angioplasty uses only local anesthetic and a small incision in the groin, so recovery is generally faster than with traditional surgery. One of the more serious complications that can occur after angioplasty and stenting is a stroke from a blockage in the brain's arteries caused by a blood clot or other debris. To prevent this from happening, you'll be given blood thinners and monitored closely.

Who should get carotid angioplasty and stenting?
If you have a carotid artery with a 70 percent blockage or more, especially if you have stroke or warning stroke symptoms, and your doctor has ruled out carotid endarterectomy, carotid angioplasty and stenting may be an option for you.

The procedure may be appropriate for people who aren't in good enough health to undergo surgery — such as those with severe heart or lung disease, those who have had radiation for neck tumors, or those who have already had a carotid endarterectomy and experience new narrowing after surgery. Sometimes, carotid angioplasty and stenting is used when the location of the narrowing (stenosis) is difficult to access with endarterectomy.

Since the procedure is fairly new, doctors don't yet know how effective carotid angioplasty with stenting is as a stroke treatment or at preventing future strokes. However, it shows promise for people who need intervention but can't have a carotid endarterectomy.

Intracranial stenting

While carotid artery disease is buildup of plaques in the neck's arteries, intracranial atherosclerosis refers to buildup of plaques farther in the brain arteries inside the skull. Because these arteries are smaller and inside the skull, they're more difficult to access — but a new procedure called intracranial stenting may be an effective stroke treatment or stroke prevention option for people with severe disease.

What is intracranial stenting?
Intracranial stenting is similar to stenting the carotid arteries. Using a small incision in the groin, doctors thread a catheter through the arteries and into the brain. Sometimes they use angioplasty to widen the affected area first; in other cases, angioplasty is not used before stent placement. Compared with the carotid arteries, the arteries inside the brain are very small and make a lot of twists and turns, so they're somewhat difficult to navigate with a catheter. Because of this, intracranial stenting requires expertise and specialized equipment.

New stents have been used the last few years that are more flexible than are those used in heart arteries. They're also self-expanding so that instead of using a balloon to open the stent, the doctor can position and open the stent without a balloon. This means less equipment on the catheter tip, making it easier to navigate through the brain's small arteries.

Researchers are still determining long-term results with intracranial stenting. In one recent study, intracranial stent placement without angioplasty reduced the risk of stroke for two years after placement, when compared with those who took only medications. Because of the small artery size, there are a variety of complications that can occur due to injury to the blood vessel from the catheter, including an artery puncture, damage to the lining of the vessel causing an artery dissection, bleeding into the brain, and stroke from artery blockage.

Who should get an intracranial stent?
Intracranial stenting isn't for everyone. Most people who have intracranial artery narrowing have good results with medications — such as aspirin and blood thinners — and lifestyle changes. This procedure is recommended only for those with symptomatic intracranial atherosclerosis that's severe — 70 percent blockage or more — and hasn't been helped by medical treatment. People with diabetes or who have blockages in arteries that can't be accessed with a catheter are not good candidates for this procedure.

If you have symptomatic atherosclerosis — meaning you've had a transient ischemic attack or a stroke — with more than 70 percent blockage, you don't have diabetes, and the affected artery is surgically accessible, you may be a candidate for intracranial stenting.

Promising treatments but limited availability

Both of these procedures are relatively new and not available at many medical centers. In order for these stroke treatment and stroke prevention options to be successful, they need to be done by a physician with expertise in stenting brain arteries. Talk to your doctor about your treatment and prevention options if you have had a stroke or TIA.

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