When is Carotid Artery Surgery necessary? What is the success rate?

Overview

Carotid Artery Surgery, also called Carotid Endarterectomy, is done to treat a condition called Carotid Artery Disease or CAD. CAD can be dangerous and if diagnosed or treated late, it can cause brain attack or brain stroke. Carotid Endarterectomy is an incisional surgery and is a better option than the minimally-invasive option called carotid angioplasty with stenting. In this article, we will learn more about the condition and also the procedure.

What is Carotid Artery Disease?

The Carotid Artery is a prominent artery that supplies blood to the brain, from the heart. Two carotid arteries run, one on each side of the neck, to supply blood through a network of small and large arteries distributed throughout the brain.

Atherosclerosis is a condition in which cholesterol, calcium and fat start depositing on the walls of the carotid artery. Over time, the deposits harden into a material called plaque. Plaque deposits can narrow down the artery, and this condition is called stenosis. In addition to plaque, blood-clots may also accumulate at that spot. The stenosis restricts or reduces timely blood-flow to the brain. This is dangerous, and is similar to plaque deposition in the coronary artery of the heart which causes a heart attack. In this case, atherosclerosis of the carotid artery causes a brain attack, also called a stroke.

Over time, pieces of the plaque start breaking off and travelling through arteries in the brain. This can cause a serious blockage in narrow blood-vessels of the brain. Similarly, the blood-clots at the above spot can travel and block narrow blood-vessels in the brain and this condition is called embolism. Whether the blockage is caused by plaque or a blood-clot, the consequence is a stroke, more specifically called an ischemic stroke. Ischemic stroke is dangerous and can cause paralysis and serious disability in the person. That is why, it must be prevented in time through accurate diagnosis, and procedures such as the carotid endarterectomy.

Also Read: Symptoms of blocked Carotid Artery and treatment

Risk Factors for Ischemic Stroke

Risk-factors that cannot be changed

Age: being older increases the risk
Race or ethnicity: African-Americans are more at risk than others
Gender: Men are more at risk than women
Genetics: A family history of CAD and stroke

Risk-factors that can be changed or treated

Hypertension or high blood-pressure
Transient ischemic attacks (TIA): which are a series of small strokes that last a few seconds or minutes and happen 5 or 6 times within a few days’ interval. They are a warning sign that a real stroke can occur one day.
A previous incidence of stroke that was treated successfully then
Asymptomatic carotid bruit or stenosis
Cardiac disease (atherosclerosis of the heart and other heart conditions)
A heart condition called Aortic arch atheromatosis
Hyperlipidaemia or excessive fat deposits in the body
Elevated levels of anticardiolipin-antibody in the blood
Diabetes mellitus
Obesity
Regular cigarette smoking
Regular alcohol consumption
Elevated levels of fibrinogen and homocysteine in the body
Low levels of serum folate in the blood
Use of oral contraceptives
A condition called microalbuminuria

Diagnosing CAD

Physical exam: The doctor will first look for signs of stroke such as numbness, difficulties in speech or vision, light-headedness or feeling dizzy, and muscle-weakness. He/she will also use a stethoscope to detect rushing sounds called ‘bruit’, in the carotid arteries.
Carotid ultrasound. Sound waves are used to create a picture of the carotid arteries and also measure the blood flow. This is a painless, minimally-invasive, and inexpensive option.
Carotid angiography or Arteriography: A type of X-ray procedure in which dye is used to highlight the arteries, and reveal the blockages. Comes with certain risks.
Magnetic resonance angiography (MRA): here, a combination of magnetic fields and radio waves are used to create a picture of the arteries. Sometimes, a contrast dye may also be used to get a clearer image.
Computed tomography angiography (CT scan): Here, X-rays help create a 3D picture of the carotid arteries. This too may use a dye.

Treatment options

Once the above tests confirm CAD in one or both carotid arteries, then the blockage must be cleared as soon as possible to reduce the risk of stroke. There are 2 options available:

Minimally-invasive option: Similar to what is done for the coronary artery, here too, balloon angioplasty with stenting is done. A deflated balloon is inserted through endoscopic means into the carotid artery, and inflated at the site of blockage. This helps push the deposits against the walls and clear the blockage. Thereafter, a metal spring called a stent is inserted and kept in place to prevent the blockage from recurring. The deflated balloon is then pulled back and out of the body.
Incisional Surgery: called Carotid Endarterectomy: As explained below

Carotid Endarterectomy

Carotid Artery Surgery, also called Carotid End-arterectomy (CEA), is an incisional or open-surgery where surgeons access the carotid artery and remove the plaque and blood-clots that have caused a blockage. The procedure is generally done under general anaesthesia but if the patient is comfortable with it, local anaesthesia is also an option. CEA will be advised by doctors if the patient has already had a stroke, or TIA, or if he/she has blockage of the artery which is severe but not total.

Before the procedure

The above tests mentioned under Diagnosis will be conducted to confirm CAD and also to know the extent. The tests will also help identify the blockage spot precisely. For a week before the procedure, the doctors may advise the patient to stop taking any medication. He/she must check into the hospital the previous night, and will not be allowed to eat or drink anything after midnight.

During

The patient is wheeled into the OR, and anaesthesia given. He/she must sleep on the side which is opposite to that which the surgeons must operate on. This way the carotid artery is easily accessible. Once the patient is no longer conscious, the doctors will clamp the carotid artery. The other carotid artery will be supplying blood to the brain. Further, the doctors may re-route the blood-flow around the artery that is being operated on.

An incision is made on the skin, above the precise spot of blockage. The carotid artery is cut gently, and the plaque and/or blood-clots removed using an assortment of tools. The normal blood-flow is restored now. The artery is then stitched back. The incision on the skin is sutured up. A tube is connected to the neck that helps drain out excess fluid.

After

The patient will remain in the hospital for 1 to 2 days during which, his vitals and neurological status will be closely monitored, after which he/she will be discharged. The patient must avoid lifting heavy objects, and refrain from driving, for up to 2 weeks after the procedure.

Also Read: How does one know if one has a blocked artery?

Risks from the procedure

CEA comes with certain risks too.

Risks from anaesthesia:

Allergies to the medicine
Breathing trouble

Risks from the surgery:

Infection at the site of incision, which can happen with any surgery
Blood clots or haemorrhage in the brain
Brain damage
Brain Stroke
Heart attack
A repeat blockage over time
Swelling near the airway
Seizures

Success Rate

In-spite of the above risks, CEA is widely preferred for its efficacy. The success rate is also good, which is encouraging. Carotid stenosis, or narrowing of the artery due to a blockage, is measured in percentage. That is, percentage of blockage in the artery.

Moderate stenosis: In patients who have already had TIA, or showing mild stroke symptoms due to moderate carotid stenosis (50-69 percent), CEA reduces the 5-year risk of stroke, or death, by 6.5 percent.
Severe stenosis: In patients who are not showing any symptoms but have a carotid stenosis of 60-99 percent, CEA reduces the 5-year risk of stroke by over 50 percent, from over 1 in 10 to less than 1 in 20.

(Source: National Institute of Neurological Disorders and Stroke (NINDS), affiliated to NIH, a govt-body in the US)

Reviewed by Dr Suresh S Venkita, Group Medical Director, Kauvery Hospitals

Kauvery Hospital is globally known for its multidisciplinary services at all its Centers of Excellence, and for its comprehensive, Avant-Grade technology, especially in diagnostics and remedial care in heart diseases, transplantation, vascular and neurosciences medicine. Located in the heart of Trichy (Tennur, Royal Road and Alexandria Road (Cantonment), Chennai, Hosur, Salem, Tirunelveli and Bengaluru, the hospital also renders adult and pediatric trauma care.

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