Carotid Artery Stenosis Of the 600,000 strokes that occur each year in the USA, it is estimated that 30-40% are caused by plaque in the carotid artery. This means that if the carotid artery plaque is discovered before a stroke occurs, the potential exists to prevent as many as 200,000 strokes annually. Carotid artery plaque is best diagnosed by ultrasound. The accuracy of the test is very dependent upon the technologist who is performing it however. The laboratory should be certified by ICAVL and ideally, the technologist and laboratory director should be Registered Vascular Technologists (RVT). Plaque with Symptoms: Plaque accumulation in the carotid artery can be associated with symptoms or it may be silent or "asymptomatic". Stroke may occur when a piece of plaque breaks free and travels to the brain or if the plaque in the carotid artery becomes so thick that it shuts down blood flow completely. Approximately 50% of people who suffer a stroke will die acutely and about 50% of survivors have some permanent neurological deficit such as paralysis or inability to speak. Another symptom that can occur due to plaque in the carotid arteries is a Transient Ischemic Attack (TIA). This is sometimes called a "mini stroke" but actually it is not a stroke. TIA occurs when a piece of plaque or blood clot on the surface of the plaque breaks free and travels to the brain but then dissolves and does not cause actual death of brain tissue (a "stroke"). The symptoms of a TIA may include: Temporary weakness or numbness of an arm or leg (or both the arm and the leg on the same side of the body) Transient loss of vision in one eye (called transient monocular blindness or TMB) When a person who has experienced a TIA is found on ultrasound exam to have a critical stenosis of the carotid artery, the risk of a stroke is thought to be about 30% during the next six months after the occurrence of the TIA. Surgery is recognized as the best option in such patients according to a national prospective randomized study of this subject called the NASCET Trial. Plaque without Symptoms: Stenosis of the carotid artery is frequently silent and the plaque accumulation is discovered only because a physician has recommended an ultrasound examination of the neck as a "screening procedure". Patients who should be screened for carotid plaque are those with: High cholesterol When plaque accumulation in the carotid artery has narrowed the artery by more than 75%, many vascular specialists will recommend that the plaque be removed. The advisability of surgery for this group of patients was proven by another prospective, randomized, national study called the ACAS Study. The safest and most effective method for dealing with carotid artery plaque is by an operation called a carotid endarterectomy. The decision to recommend surgery for any individual patient must be considered on a case by case basis by the physicians and surgeon who are treating that individual patient. Carotid Endarterectomy: This operation is performed via a small incision on the side of the neck. The artery is opened and the plaque is removed. Frequently, the vascular surgeon will enlarge the artery by sewing a patch of vein or artificial material onto the artery after the plaque is removed. The operation is safe, extremely effective in preventing stroke and quite durable. The success of this operation has been shown to be very dependent upon the experience of the surgeon. Results of operation vary from complication rates (meaning stroke during the operation itself) of 1-2% to as high as 10% with high volume surgeons having lower stroke rates than surgeons with a low volume of carotid surgery. Recurrence rates of carotid stenosis are very low-particularly if a vein patch is used to enlarge the carotid artery after the plaque is removed. Questions to ask the surgeon regarding Carotid Endarterectomy |
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Plaque removed
Plaque removed from carotid artery .
Illustration shows plaque in carotid artery (upper right). |
