Carotid Artery Disease
Carotid artery disease occurs when deposits build up inside a carotid artery. The primary surgical treatments for carotid artery disease are carotid endarterectomy (CEA) and carotid artery angioplasty with stenting (CAS).
Deposits inside artery walls are known as plaques. Plaques are comprised of fats, cholesterols, proteins and other materials that cause artery walls to become thick and stiff. For this reason plaque buildup is sometimes called “hardening of the arteries,” or atherosclerosis (sclerosis = hardening).
Carotid artery stenosis, a narrowing of the carotid arteries, occurs when plaques interfere with the flow of blood. Stenosis of the carotid arteries may prevent sufficient blood from reaching the brain. When this occurs, the result can be a stroke, a medical emergency that can lead to permanent disability or death.
Carotid artery disease may compromise the brain’s blood supply via one of three mechanisms:
- Carotid artery stenosis. Plaques may grow large enough simply to block the flow of blood through the artery.
- Plaques can rupture and leak their contents. Blood clots form to stop the leak, and these clots may obstruct blood flow through the vessel.
- Part of a clot from a plaque’s rupture may detach from the rest of the clot. This detached section may travel through the bloodstream until it lodges in a narrow vessel in the brain, blocking that vessel.
Carotid artery disease may have few or no noticeable symptoms until it is quite advanced. In some individuals, the first symptom is a stroke.
Symptoms of a stroke include:
- Sudden weakness or numbness, especially on one side of the face or body
- Sudden severe headache
- Sudden confusion
- Sudden trouble seeing
- Sudden dizziness, loss of balance or trouble walking
These symptoms indicate a potential medical emergency. If someone shows signs of a stroke, obtain medical help immediately.
Some people with carotid artery disease may experience transient ischemic attacks (TIAs), or mini-strokes. These events are characterized by symptoms similar to those of a stroke, but the symptoms of TIAs resolve on their own over the course of minutes or hours. Though the symptoms abate, TIAs should not be ignored because they may indicate that a stroke is impending. Prompt treatment for the cause of the TIA may prevent a stroke.
As blood travels through a stenotic carotid artery, the blood may make a whooshing noise called a bruit that a doctor may be able to hear with a stethoscope. This is not a foolproof diagnostic test: Not all cases of carotid artery stenosis produce a bruit, and a bruit can also exist without carotid artery stenosis. But the presence of a bruit often prompts further testing.
The most common imaging scan used to find carotid artery disease is an ultrasound of the artery. This test uses sound waves to produce images of the artery on a computer screen.
If more information is necessary, more detailed scans are available:
- Angiography: Uses a special X-ray to reveal blood flow through arteries. A substance called a contrast dye may be injected into the bloodstream to make the arteries stand out more clearly on the scan.
- Magnetic resonance angiography: Uses magnets and radio waves to produce images of arteries. May be performed with or without contrast dye.
- Computed tomography angiography: Uses a computer and X-rays from various angles to produce images of arteries. May be performed with or without contrast dye.
Carotid artery disease sometimes has its beginnings as early as childhood. Microscopic injuries in artery walls may begin a cascade of reactions that can result in plaque formation, either gradually, over the course of decades or—particularly in adults—rapidly.
Many factors influence the injury of artery walls and the development of plaques. Some are independent of lifestyle. These include:
- Genetic predisposition
Risk factors affected by lifestyle include:
- High blood pressure
- Tobacco use
- High cholesterol
The goal of treatment for carotid artery disease is to prevent a stroke. Some patients may be able to mitigate their risk adequately through medication and lifestyle changes. But for other patients, such as those who have had TIAs or whose blood flow is severely compromised, surgery may be the better option.
The two standard surgical treatments for carotid artery disease are:
- Carotid endarterectomy (CEA): In this procedure, the surgeon uses an operating microscope and extremely fine instruments to make a tiny incision in an artery wall, remove the plaque and suture the artery wall closed again, restoring normal blood flow.
- Carotid artery angioplasty with stenting (CAS): This is a minimally invasive procedure. A surgeon threads a catheter from the groin through blood vessels up to the carotid artery. A device like a small balloon is inflated in the carotid artery, opening it wider. A stent is put in place to hold the artery open. The surgeon leaves the stent in place and removes the balloon and the catheter.