Carotid occlusive disease, also called carotid stenosis, occurs when one or both of the carotid arteries in the neck, which supply blood to the brain, becomes narrowed or blocked. The narrowing usually is the result of the buildup of plaque, which is made up of fatty material and blood platelets, along the vessel walls. If a piece of the fatty deposit breaks off and blocks one of the arteries in the brain itself, blood flow to the brain is compromised, which may lead to a transient ischemic attack (TIA or “mini-stroke”) or, in severe cases, a stroke.
The risk factors for carotid occlusive disease include high blood pressure, heart disease, diabetes, smoking, obesity, family history, elevated homocysteine levels, and TIAs.
A TIA, or “mini-stroke,” is a temporary condition is which the blood flow to a part of the brain is restricted, leading to transient neurological deficits. A stroke occurs when the blood supply to a part of the brain is completely blocked causing destruction of brain tissue. Stroke is the third leading cause of death in United States-more than 150,000 deaths each year-and approximately 50 percent of all strokes are caused by buildup of plaque in the arteries.
A carotid occlusion does not always lead to a stroke. Sometimes other arteries will expand to transport the blood the brain needs if the carotid arteries are blocked. Also, the carotid arteries are large enough that a significant blockage still will still allow enough blood to flow to supply the brain. A serious blockage however, increases the risk of stroke.
Carotid stenosis is assessed first with a thorough physical examination. This examination can reveal specific neurological, motor, and sensory deficits that can provide clues about both the extent and location of an occlusion. In addition, physicians may be able to hear changes in blood flow in the carotid arteries with a stethoscope.
A complete diagnostic workup also includes carotid Duplex ultrasound followed by magnetic resonance imaging (MRI) and computed tomography (CT) scans, which are noninvasive techniques. Complex cases may require an informal angiogram in which a catheter is inserted into the vessels to project a dye that permits visualization of the blood vessels.
Treatment, which is determined by the extent of the narrowing and the condition of the patient, may include medication to treat the underlying risk factors associated with carotid occlusive disease, including antihypertensives for high blood pressure, medication to reduce cholesterol levels, and diabetes medication.
Procedures such as carotid endartectomy or other endovascular approaches can also be used to treat carotid stenosis. Carotid endarterctomy is the surgical removal of the occluding mass from the lining of the artery to allow blood to flow into the brain normally.
Angioplasty and stenting are endovascular procedures used to open flow through the artery with the use of a catheter. The catheter usually is inserted in an artery in the groin and guided up to the site of the occlusion. Once there, it can deploy a balloon that pushes open the narrow artery and displaces the plaque. Then a stent, a self-expanding tube, can be implanted to hold the artery open and maintain blood flow.
Carotid occlusive disease is a complex condition, and should be addressed at major centers with experts experienced in its treatment.