Carotid arteries are the major blood vessels on each side of the neck that supply blood to the brain, face and neck. These arteries extend from the aorta in the chest to the base of the skull.
Over time, the arteries can harden and cause a build-up of plaque (calcium, cholesterol, and fibrous tissue deposits) on the walls of the arteries. This plaque build-up can narrow and stiffen the arteries. The progressive plaque build-up can reduce the blood flow through the arteries or cause the formation of blood clots. Such narrowed carotid arteries can be treated by using stents.
Carotid artery stenting (CAS) involves the insertion of a metal-mesh tube, called a stent, at the site of clogged arteries, to expand the lumen of the arteries and increase the blood flow to the brain.
What are the indications and contraindications for CAS?
The indications for CAS include:
- High risk of stroke
- Carotid artery blockage of 70 percent or more
- Intolerance to general anaesthesia for carotid endarterectomy (an open surgery to remove the plaques in carotid arteries and to reduce the risk of stroke)
- Damage to the contralateral vocal cord caused by previous carotid endarterectomy or neck surgery
- Narrowing of carotid artery after previous CEA
- Neck irradiation
The contraindications for CAS are:
- Allergic reaction to intravenous (IV) contrast dye in the past
- Unstable carotid or aortic arch plaque
- A recent stroke in less than 14 days
- Total thrombotic occlusion of carotid artery
What are the complications of CAS?
Here are some complications that may occur during or after CAS:
- An embolism, blockage due to a clot or debris in an artery in the brain, a serious complication which can cause a stroke.
- Formation of a blood clot along the stent or a tear in the artery wall (dissection).
- Restenosis, the blockage of the carotid artery after the procedure.
- Kidney damage, particularly in individuals with kidney problems, caused by the dye used for angiogram.
- Bleeding from the incision site in the arm or groin artery, known as false aneurysm or hematoma (an unusual complication).
- Mild tenderness and bruising at the puncture site, which usually resolves over time.
The factors that increase the chance of complications during CAS include:
- Age > 80 years
- High blood pressure
- Allergy to contrast material
- Sharp bends or other structural abnormalities in the carotid arteries
- Significant atherosclerosis or plaque build-up in or near the carotid artery
- Widespread blockages in the arteries in the legs and arms
- Poor kidney function
How to prepare for CAS?
When planning for the procedure, inform your doctor about:
- All the medicines that you take, including over-the-counter medicines, blood thinners, herbs, supplements, etc.
- Habits like smoking; your doctor may help you quit smoking
- Any changes in your health, like a fever
- Are or may be pregnant
- Allergies to medicines such as iodine, anaesthesia, or contrast dyes
- Any pacemakers that you have
- Any other medical condition that you have
Some tests may be performed before the procedure, including:
- Blood tests, to check for infection and anaemia
- A chest X-ray, to view the heart and lungs
- An electrocardiogram (ECG), to assess the heart rhythm
- Ultrasound of the neck, to assess the carotid artery
- Computed Tomography (CT) angiogram of the blood vessels in the neck and head
Your healthcare team may give you some instructions to prepare for the procedure, which may include:
- You may be asked to stop some medicines, such as blood thinners, a few days before the procedure
- Ask your doctor which medicines you can take on the day of the procedure, and which medicines you should stop taking.
- Do not eat or drink after midnight, the night before CAS.
- Make sure you have an adult to drive you home on the day of the procedure
What happens during CAS?
Although the exact steps of the procedure may vary, a typical CAS may go like this:
- An intravenous (IV) line will be put in the arm before the procedure. Sedation will be given through this IV line to help you relax and sleep.
- Local anaesthesia is injected near the groin region.
- A small incision is made in the blood vessel in the groin region.
- A thin, flexible tube called catheter, with a balloon at its tip is inserted into this incision.
- The catheter is threaded through the blood vessel into the carotid artery.
- X-ray images may be used to guide the catheter to reach the blocked region in the carotid artery.
- The balloon is inflated and deflated several times inside the narrow part of the carotid artery.
- A compressed stent is then inserted using the catheter to reach the affected area.
- Once the stent is at the precise location, it is released. The stent expands to fit the artery.
- The balloon catheter may be used to expand the stent further.
- The balloon is deflated, and the catheter is removed.
What happens after the procedure?
After the procedure, you will be moved to the recovery room. Your vitals, like your breathing and heart rate, will be monitored. Pain medicines will be given if needed. You may have to lie down, without bending your legs for few hours to prevent bleeding from the incision site.
You can go home on the same day of the procedure, but some patients may have to stay in the hospital for the night. You should ask a family member or a friend to drive you home.
After leaving the hospital, you may have some pain or a bruise near the incision site. You may be given certain over-the-counter pain medicines, drugs to prevent blood clot formation or spasm of the blood vessels; your healthcare provider will instruct you the dose and when you should take these medicines. Rest well and avoid strenuous exercise for the next 24 hours at least.
Call your doctor immediately if you have:
- Severe pain or swelling at the incision site that is progressing
- Blood or fluid leakages from the incision site
- Redness or warmth at the incision site
- Chest pain
What measures do I take to stay healthy after CAS?
CAS opens the artery and ensures good blood supply to the brain. But this procedure does not stop building-up of plaque in the arteries. Therefore, to preventing hardening of the arteries, plaque formation and clogging of the arteries, take the following measures:
- Eat foods containing low calories, cholesterol, and saturated fat.
- Exercise regularly, particularly aerobic exercises like walking.
- Maintain an ideal body weight.
- Quit smoking.