Carotid stenting for carotid artery stenosis
Carotid artery stenting is a procedure in which your vascular surgeon inserts a slender, metal-mesh tube, called a stent, which expands inside your carotid artery to increase blood flow in areas blocked by plaque.
When your physician wants to treat a blocked carotid artery, he or she may recommend that you have a stent inserted as an alternative to surgical removal of the plaque, known as carotid endarterectomy. During the carotid stenting procedure, your physician inserts a stent into your carotid artery after performing angioplasty. Angioplasty uses a balloon inflated in the narrowed part of the artery to flatten the plaque and open the artery. The stent holds the artery open by holding back the flattened plaque like scaffolding.
The procedure usually takes place in a Radiology suite. Before the procedure begins, your physician will connect you to a monitor that shows your heart rate and blood pressure. During the procedure, your physician will likely talk with you and may instruct you to squeeze a small toy or ball so that he or she can monitor your brain function. While some physicians may perform the procedure under general anesthesia, in most instances, the procedure is performed while you are awake and alert.
Your physician will give you medications to prevent clots, to control your heart rate, and a local anesthetic to numb the catheter insertion area. Your physician may not give you any other medications so you will be alert to follow instructions during the procedure. Your physician then locates the areas of narrowing in your arteries by injecting a dye into your arteries and taking x -rays. Physicians can see your arteries and use the x-rays to guide them to the blockage.
Before inserting the stent, your physician will usually perform angioplasty. In angioplasty, your physician inserts a long, thin tube called a catheter with an attached balloon into a small incision or puncture over an artery in your arm or groin. Your physician guides the catheter to the blockage site in your carotid artery using live x ray imaging. You will not feel the catheters as they move through your arteries because there are no nerve endings inside your arteries.
At this point in the procedure, your physician may insert a small balloon, basket, or filter called an embolic protection device. This device helps to prevent strokes by catching the clots or debris that may break away from the plaque during the procedure.
Illustration of a carotid stent within a carotid artery
At the blockage site, your physician inflates and deflates the angioplasty balloon to flatten the plaque and widen the space where the blood flows through. After the artery is open, your physician then removes the catheter with the balloon attached.
Using a different catheter, your physician guides a compressed stent to the same area in your carotid artery. Once the stent is in place, your physician releases it. The stent then expands to fit the artery. In most cases, your physician then uses a balloon catheter to further expand the stent. Your physician then removes the stent-carrying catheter and any embolic protection devices. Stents remain permanently in your carotid artery.
Carotid stenting usually takes about 1-2 hours but may take longer in some circumstances.
What to expect after surgery
Immediately after the procedure, your physician will apply pressure to the catheter insertion site in the groin or arm for 15 to 30 minutes to allow it to close and prevent bleeding. Sometimes to close the incision, your physician may use a cork-like closure device or stitches that dissolve.
If your physician inserts the catheters and other instruments through your femoral artery, you will be asked to stay in bed for the next several hours so that the puncture site can be watched for any complications, such as bleeding. Patients undergoing this procedure usually spend 1-2 days in the hospital.
Why this surgery is done
Your carotid arteries are located on each side of your neck and extend from your aorta in your chest to the base of your skull. These arteries supply blood to your brain. You have one main carotid artery on each side, and each of these divides into two major branches, the external and the internal. The external carotid supplies blood to your face and scalp. Your internal carotid artery is more important because it supplies blood to the brain.
Hardening of the arteries, also known as atherosclerosis, can cause the build up of plaque. In hardening of the arteries, plaque builds up in the walls of your arteries as you age. Cholesterol, calcium, and fibrous tissue make up the plaque. As more plaque builds up, your arteries can narrow and stiffen. Eventually, enough plaque may build up to reduce blood flow through your arteries, or cause blood clots or pieces of the plaque to break away and block the arteries in the brain beyond the plaque.
When plaque builds up and reduces blood flow in your carotid arteries, you have carotid artery disease. This is a serious issue because clots can form on the plaque and block the blood flow to your brain. If a clot or plaque blocks the blood flow to your brain, it can cause an ischemic stroke, which can cause brain damage or death. An ischemic stroke is a stroke that occurs because there is a lack of blood flow to cells in the brain. Another related problem that the plaque can cause is an arterial embolism. This occurs when a small piece of plaque or a blood clot breaks away from the site where it formed and blocks another artery downstream. If a clot blocks a tiny artery in the brain, it may cause a transient ischemic attack, also known as a mini-stroke.
Blockage by a clot or other debris in an artery in your brain, called an embolism, is the most serious complication that can occur after carotid stenting. This blockage can cause a stroke. Other complications that may cause a stroke include a blood clot forming along the stent or a tear in the artery wall called a dissection. The re-blockage of the carotid artery, called restenosis, is another possible complication. The dye used for the angiogram can sometimes cause damage to the kidneys, especially in people who already have kidney trouble. Bleeding from the puncture site in the groin or arm artery, called a hematoma or a false aneurysm, can also occur, but this is unusual. Bruising and mild tenderness at the puncture site is common, however, and usually resolves with time.
Other factors that may increase your chance for having complications during carotid stenting include:
- High blood pressure
- An allergy to contrast dye;
- Hardened (calcified) and long narrowing of the carotid artery
- Sharp bends or other difficult anatomies in the carotid arteries
- Irregular-looking plaque
- Significant plaque or atherosclerosis of the aorta near the beginning of the carotid artery
- An age more than 80 years
- Extensive blockages in the arm and leg arteries
When you go home
Your physician may instruct you not to lift anything more than about 5 to 10 pounds, after you return home, to avoid any pressure on the incision for several weeks. Your physician may also instruct you not to take a bath for a few days (but showers are fine), and to drink plenty of water to help flush the dye out of your system. You will be advised to take blood thinning medications and also be scheduled for periodic follow-up examinations, including carotid ultrasound examinations, to monitor the function of your stent over time.
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