Definition
You may have heard of coronary heart disease, a disease caused by blockage of the coronary arteries that supply blood to the heart due to lipid deposits called atheromatous plaques.
The same plaque formation can occur in the carotid arteries, a pair of vessels responsible for supplying blood to the head and brain. The greatest risk of carotid artery disease lies in the blockage of the carotid arteries that supply blood to the brain, and the obstruction of blood flow leads to stroke. Carotid artery disease is often overlooked because of its slow progression. A stroke or transient ischemic attack is a sign of a distant stroke and may be an early sign of carotid artery disease.
Treatment for carotid artery disease usually includes a combination of lifestyle changes, medications and, in some cases, surgery or stenting.
Symptoms
The early stages of carotid artery disease are usually not accompanied by any signs or symptoms. You and your doctor may not know you have carotid artery disease unless it is so severe that the blood supply to the brain is reduced. At this time, you may experience the following signs and symptoms.
Sudden weakness, numbness, or paralysis of the face, upper extremities, lower extremities, and typically one limb.
Shortness or slurring of words, or difficulty understanding what is being said.
sudden onset of unilateral blindness.
If you have any of these signs or symptoms, you may have had a stroke. Please seek medical attention immediately.
Even if these signs and symptoms last only a short time – usually less than 1 hour, but medically less than 24 hours – and then you return to normal, tell your doctor right away. You may have had a transient ischemic attack, a brief shortage of blood supply to the brain. Transient ischemic attacks are an important sign that you are at high risk of having a stroke and therefore should not be ignored. Most patients who have a stroke due to carotid artery disease have had a transient ischemic attack before the stroke.
Etiology
A normal healthy carotid artery – like any healthy artery – is a smooth and flexible vessel that provides a good pathway for blood flow. You can feel the pulsation of the carotid arteries by placing your fingers under your jawbone, on either side of the bilateral laryngeal nodes. The carotid arteries carry oxygen-rich, nutrient-rich blood to the cerebral cortex and other vital brain structures that sustain the body’s daily functions.
Over time, the carotid arteries become stiff and narrow due to the deposition of plaque, a process also known as atherosclerosis. Plaque consists of cholesterol crystals, calcium, fibrous tissue, and other cellular debris that collect to cause microscopic damage to the arterial lining. When these plaque deposits cause the lumen of the carotid artery to narrow and thus reduce blood flow, it is called carotid artery disease.
Risk factors
Those factors that strain the arteries and increase the risk of vascular damage and increase atheromatous plaque deposition include the following.
Age: as we age, the arteries become less elastic and more susceptible to damage.
Hypertension: High blood pressure is an important risk factor for carotid artery disease. Excessive blood pressure makes artery walls weaker and more susceptible to damage.
Abnormal lipid levels: high LDL – harmful cholesterol – and high triglycerides – a blood lipid component that promotes atheromatous plaque deposits.
Diabetes: diabetes is not only an abnormality of blood sugar, but also affects the efficiency of lipid metabolism and is a higher risk of hypertension and atherosclerosis.
Obesity: being overweight increases the risk of hypertension, atherosclerosis, and diabetes.
Genetic factors: A family history of atherosclerosis or coronary heart disease increases the risk of carotid artery disease.
Lack of exercise: Lack of exercise contributes to the development of a range of diseases, including hypertension, diabetes, and obesity.
Often, these risk factors, which are similar to those for coronary artery disease, are higher when they are present together than when they are present alone. In fact, people with carotid artery disease are likely to have coronary artery disease as well.
When to seek medical attention
It is important to inform your doctor if you have risk factors for carotid artery disease. Your doctor may perform tests to determine the exact status of your arteries. Even if there are no signs or symptoms, your doctor may recommend proactive measures to manage the risk factors to avoid a stroke.
If you have any signs and symptoms of transient ischemic attack or stroke, such as numbness, slurred speech, or loss of vision, go to the emergency room. Just because these symptoms are self-resolving does not mean they can be ignored. Early detection and treatment of carotid artery disease can prevent disabling strokes.
Detection and diagnosis
In addition to asking about past medical history, risk factors, and any signs and symptoms present, your doctor may perform a number of tests to assess the health of the carotid arteries.
Physical examination: The doctor may hear a swooshing blowing sound like a murmur next to the carotid artery in the neck, which is indicative of arterial stenosis. The doctor may look for cholesterol fragments (cholesterol plugs) in the retinal smile vessels during a fundus exam. A test comparing blood pressure in both eyes and in both upper extremities may be required.
Ultrasound: Doppler ultrasound is a common, non-invasive test used to detect carotid artery disease. This test, unlike conventional ultrasound, uses high-frequency sound waves to assess blood flow status and blood pressure, as well as to show possible narrowing of the vessels.
Other imaging tests: If Doppler ultrasound does not provide enough information, a more accurate imaging test such as CT or MRA is needed. by injecting contrast into the blood vessels, the doctor can obtain a detailed picture of the neck and cerebral vessels by CT or MRI.
Sometimes a more traditional and invasive imaging test called a cerebral angiogram is needed, which is not commonly done because of the risk of stroke. This test is a combination of an X-ray imaging system and an intra-arterial injection of contrast. To begin, the radiologist inserts a small flexible catheter into the vessel through a small incision in the groin and then injects a contrast medium into the vessel before taking a picture. These contrast agents allow the artery to be clearly visualized on x-ray.
Complications
The most serious complication of carotid artery disease is stroke. Carotid artery disease can increase the risk of stroke in several different ways.
Decreased blood flow. Due to the presence of atherosclerotic plaque, the lumen of the carotid artery can be severely narrowed causing the brain to not receive an adequate blood supply.
Plaque rupture. Fragments of plaque can be dislodged into the small blood vessels of the brain. These fragments can cause occlusion of the lumen of the small vessels, which can lead to ischemia and stroke in the area of the brain they supply.
Thrombotic blockage: Some carotid plaques are prone to rupture resulting in an unsmooth inner surface of the artery. When this occurs, the body may respond by repairing the damage, platelets that help clotting may accumulate locally, and a large thrombus may form in the carotid or cerebral artery slowing blood flow or blocking it completely, leading to a stroke.
Stroke can lead to permanent brain damage and muscle atrophy, which can be fatal in severe cases.
Treatment and medications
The goal of treatment for carotid artery disease is to prevent strokes. Treatment depends on the degree of carotid artery stenosis. In patients with mild to moderate stenosis, lifestyle changes and medications can be effective in preventing stroke. However, if the blockage is severe, or if a transient ischemic attack or stroke has already occurred, surgery or stenting may be necessary.
Lifestyle changes
Quitting smoking, losing weight, eating a healthy diet, and getting regular exercise are important measures to reduce arterial pressure and slow down the process of atherosclerosis. A low-salt diet may also help.
It is also important to treat chronic conditions as recommended by your doctor, and if you have high blood pressure, it is important to control it. Likewise, it is important to control blood sugar in diabetic patients and to lower blood lipids in hyperlipidemic patients.
Medications
Your doctor may recommend that you take aspirin or other medications to reduce blood viscosity to avoid dangerous blood clots. Antihypertensive medications, such as ACEI or calcium antagonists, or inhibitors to lower lipids, may also be recommended to control blood pressure.
Surgery
If the carotid artery is severely narrowed, especially if you have had a transient ischemic attack or a stroke, it is best to have the blockage removed by surgical dissection of the carotid artery. There are two types of surgery.
Carotid endarterectomy: This procedure is the most common way to treat severe carotid artery stenosis. Under local or general anesthesia, an incision is made in the front of the neck, and the surgeon cuts open the affected carotid artery and removes the plaque within it. Most patients are discharged from the hospital 48 hours after the procedure. The risk of the procedure is low and can be tolerated in good health, even in people over 80 years of age. Studies have shown that the procedure has a lasting effect and helps prevent strokes.
Carotid angioplasty and stenting: In some patients, carotid endarterectomy cannot be performed because the carotid artery is narrowed or obstructed in a location that is difficult to reach. There are also specific conditions, such as severe cardiopulmonary disease, a history of previous neck surgery or radiation therapy for a neck tumor, or renal failure, where the risk of surgery is too great, in which case your doctor may recommend a balloon dilation treatment called carotid angioplasty as well as stenting.
After local anesthesia, the doctor inserts a long catheter through the femoral artery to reach the narrowed carotid artery through the bloodstream. A tiny catheter with a balloon on the end is dilated at the stenosis, followed by the insertion of a metal woven mesh tubular stent to keep the carotid artery dilated and prevent the lumen from retracting after dilatation. In most cases, a small mesh device, also called a thrombus protection or distal protection device, is placed at the distal end of the stent to prevent strokes caused by fragments of plaque dislodged during manipulation. When the stent is implanted, this protection is removed. Discharge from the hospital is usually the second day after the procedure. Most patients go home and are able to perform normal activities. Because this technology is new, its durability and long-term efficacy in preventing stroke are still being studied.
Lifestyle and daily medication
A proper lifestyle can help prevent or slow down the progression of carotid artery disease, thereby preventing transient ischemic attacks and strokes. These recommendations are as follows.
Quit smoking: Stopping smoking reduces the pressure in the arteries, thus reducing transient ischemia and the subline of stroke attacks. There is no difference in the incidence of stroke between smokers and nonsmokers years after quitting, so it is never too late to quit.
Limit cholesterol and fat intake: Reducing cholesterol and fat intake, especially saturated fat, in the daily diet can reduce the formation of atheromatous plaques.
Eat a variety of fruits and vegetables: These foods contain potassium, folic acid, and antioxidants, which can prevent transient ischemic attacks and strokes.
Low sodium diet: Restricting sodium intake may not prevent hypertension, but excessive sodium intake can increase blood pressure in those who are sensitive to sodium. In healthy adults, the daily sodium intake recommended by most experts is 1500-2400 mg/day. If you have hypertension, keeping your sodium intake at the low end of the normal range can help lower your blood pressure.
Regular exercise: Exercise can be a way to lower blood pressure and increase HDL, which is the beneficial cholesterol, thus improving the health status of blood vessels and heart. Regular exercise also helps to lose weight, lower blood sugar and reduce stress. If you have high blood pressure, 30 minutes of moderate aerobic exercise most days of the week is one of the few measures that can lower blood pressure without medication.
Limit alcohol intake: If you can’t quit drinking, drink in moderation. The recommended amount of alcohol is one drink a day for women and no more than two drinks for men.
Maintain a healthy weight: Being overweight can increase other risk factors such as high blood pressure, cardiovascular disease and diabetes. Weight loss through controlled diet and exercise can lower blood pressure and improve blood lipid levels.
Control chronic diseases: Diabetes and hypertension can be treated through diet, exercise, and weight control, and medications can be used if necessary.