Definition and Overview
A carotid surgery, more specifically known as a carotid endarterectomy, is a surgical procedure wherein the inner lining of the carotid arteries is removed in the event of blockage that restricts efficient blood flow. The purpose of the surgery is to remove cholesterol buildup and fatty deposits that have accumulated in the arteries.
Who should undergo and expected results
Carotid surgery is necessary for people diagnosed with:
- Carotid artery stenosis or carotid artery disease
- Atherosclerosis, or hardening of the arteries
The above conditions can trigger either an ischemic stroke or a transient ischaemic stroke, wherein the carotid artery is completely blocked and blood is unable to flow to the brain. In some cases, a blood clot may also form along the arteries; if a piece of the clot breaks off, there is a tendency for it to travel to the brain, where it can trigger an embolic stroke.
Narrowed and hardened arteries are graded depending on the severity of the blockage. Mild stenosis is when only up to 49% of the artery is blocked, moderate stenosis is when 50 to 69% is blocked, and severe stenosis is when 70 to 99% of the artery is blocked. Carotid surgery is most beneficial for patients who have moderate and severe blockage in one or both of their arteries. The presence and extent of blockage can be determined using brain imaging scans, such as a duplex ultrasound scan, a CT scan, a computed tomography angiogram (CTA) or magnetic resonance angiography (MRA). In most cases, doctors first use an ultrasound to detect stenosis and determine a person's chance of benefiting from a surgery. If narrowed arteries are detected, further tests may be performed to determine the extent of the blockage.
However, doctors do not wait until severe symptoms such as a stroke occur. This is because in some cases, the condition is asymptomatic, and doctors only discover a hardened or narrowed artery when conducting tests for other purposes. Symptomatic stenosis, on the other hand, may cause the following symptoms:
- Vision loss in one eye
- Speech difficulties
- Numbness or weakness in the face and limbs
- Facial drooping on one side
A person's risk of requiring carotid surgery at some point in life may be aggravated by factors that cause plaque build-up, such as:
- High blood pressure
- High-fat diet
A carotid surgery is expected to significantly reduce a person's risk of suffering a stroke or other symptoms related to carotid artery stenosis and atherosclerosis. Also, patients who have suffered from a stroke and do not seek surgical treatment have a higher risk of suffering from another attack, but a carotid endarterectomy can reduce this risk by a third.
Patients suffering from blocked arteries can also choose whether to have a carotid endarterectomy or a carotid artery stent placement, the latter of which is less invasive. A stent placement, which does not require any incision, simply widens the artery so that blood can flow properly. However, this type of minimally invasive procedure is not a long-term solution and has been linked to a greater risk of post-operative stroke compared to an endarterectomy. Thus, it is only used for patients who are not cleared for an endarterectomy for any possible reason.
How the procedure works
A carotid endarterectomy is done by making a small incision along the carotid artery, specifically at the place where it has narrowed, to remove the plaque that has accumulated there. The incision usually ranges between 7 and 10 centimetres or 2.5 to 4 inches, and is generally made between the breastbone and the jaw. Once the fatty deposits have been removed, the artery is stitched or patched. In some cases, the surgeon may temporarily leave a tube to drain out any remaining blood that might leak out after the surgery. If two arteries are to be operated on, the surgeon will work on one side first, with the second operation following after a few weeks.
This procedure can be performed either under local or general anesthesia, with the former allowing the surgeon to monitor brain function during the surgery. Both, however, are considered safe and no significant difference between the two types of anesthetics during carotid surgery has been found.
During the surgery, the blood flow to the brain may be maintained using a shunt, or a small tube made of plastic which purpose is to divert the blood so that it flows continuously to the brain while the surgery is being performed. If a shunt is not used, the carotid artery is simply clamped to restrict blood flow until the surgery is finished.
Since carotid surgery is a sensitive procedure, it requires a hospital stay, with most patients going home around 48 hours after the procedure. It is normal to experience some discomfort and numbness in the neck, but these should go away on their own shortly after the procedure.
Possible risks and complications
There is a small risk that some complications may arise during or after the surgery. Although rare, these complications can be serious and life-threatening. In every carotid surgery, there is a risk of stroke or even death. However, studies show that the risk of stroke and death is still higher among patients suffering from carotid artery stenosis and have decided to forego surgery.
Less serious complications also include:
- Pain or numbness at the incision site
- Temporary nerve problems, which causes temporary weakness and numbness on the side of the face that may take a month to resolve
A person's risk of experiencing complications during and after a carotid surgery depends on:
- Lifestyle, smoker or alcoholic
- Previously had a stroke
- Whether both arteries are blocked
- Other health/ medical conditions (Diabetes, Hypertension, etc)
A carotid surgery also does not ensure that the artery will not become blocked again. Up to 4% of patients who have undergone carotid surgery requires another procedure to treat recurrent stenosis.
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Silva MB Jr., Choi L, Cheng CC. Peripheral arterial occlusive disease. In: In: Townsend CM, Beauchamp RD, Evers BM, Mattox KL, eds. Sabiston Textbook of Surgery. 19th ed. Philadelphia, PA: Elsevier Saunders; 2012:chap 63.
Society for Vascular Nursing. 2009 Clinical practice guideline for patients undergoing carotid endarterectomy (CEA). JVasc Nurs. 2010;28:21-46.