Carotid Stenting

July 9, 2006 Carotid Artery Disease The carotid arteries are the main vessels that supply blood to the head. There is one main carotid artery on each side of the neck. Each of those vessels subdivides into two branches. The internal carotid arteries supply blood to the brain. The external carotid arteries supply blood to the face and scalp. Carotid artery disease (sometimes referred to as carotid artery stenosis) is a narrowing or blockage in an area of the carotid arteries. The condition is usually caused when plaque builds along the inner walls of the arteries (atherosclerosis). If the plaque "cracks," the body senses the problem as an "injury" and sends platelets to form clots and "heal" the injury. The clot can significantly slow or block the flow of blood through the affected artery. Since the carotid arteries supply blood to the brain, the clot can interfere with oxygen delivery to a part of the brain, causing a stroke. In some cases, the plaque itself can build up enough to impede blood flow through the artery. Researchers estimate about 10 to 15 percent of ischemic strokes (those caused by a blockage) occur from carotid stenosis. Carotid artery disease is more common in older men and women. The Society for Vascular Surgery estimates one percent of adults 50 to 59 have significant narrowing in their carotid arteries. By 80 to 89, about 10 percent of American adults have significant carotid artery disease. Patients often dont have any symptoms until they develop signs of stroke. Treating Carotid Artery Disease Initially, doctors may try lifestyle changes (like stopping smoking, exercise and diet modifications) and medications to try to manage carotid artery disease. Antiplatelet drugs can reduce the chance of clot formation. Statins may lower cholesterol levels and decrease the thickness of plaque along the walls of the carotid arteries. High blood pressure medication may be prescribed to control elevated blood pressure, an important risk factor in development of a stroke. When medications and lifestyle modifications arent enough, doctors may recommend surgery. The gold standard of surgery for carotid artery disease is a procedure called a carotid endarterectomy. An incision is made into the neck to access the artery. The artery is clamped to temporarily stop blood flow. Then, an incision is made into the wall of the artery at the site of the blockage. The plaque is peeled from the wall and the artery is stitched closed. The clamp is removed and the surgeon watches for any excess bleeding. The neck incision is then closed. Research suggests about 180,000 carotid endarterectomies are performed in the U.S. each year. The procedure is usually reserved for patients with severe or progressing carotid artery disease. (The American Academy of Neurology recently issued guidelines against the use of carotid endarterectomy in asymptomatic patients with blockages of less than 50 percent.) Carotid Stenting Some doctors are now using stents to open up narrowed carotid arteries. A stent is a hollow, flexible metal tube that acts like a scaffold to hold open the walls of an artery. The devices are like those used to prop open blocked arteries in the heart. First, doctors make a tiny nick into an artery in the groin. Using X-rays for guidance, a guidewire is fed through the circulatory system to the area of narrowing in the carotid artery. A tiny filter at the end of the guidewire is opened like an umbrella to catch any debris that may break loose and prevents the material from traveling to the brain and causing a stroke. Next, a balloon-tipped catheter is snaked over the guidewire to the target area. Once in place, the balloon is inflated. As the balloon expands, it presses the plaque against the walls of the artery. The balloon is withdrawn, Then a stent is guided to the area. The stent is usually self-expanding. Once it is released from the catheter, it automatically opens and conforms to the shape of the inner walls. The filter and catheter are removed. Placement of a stent is a less invasive procedure than carotid endarterectomy. The stent doesnt require a neck incision and patients may avoid the need for general anesthesia. Thus, stenting may be a safer option for patients who arent candidates for endarterectomy due to potential complications or underlying medical conditions. There is less blood loss, a shorter hospital stay and faster recovery. Researchers are still debating whether stenting is actually a better procedure over endarterectomy for most patients. Several studies have compared the two procedures. Research from the SAPPHIRE (Stenting and Angioplasty in Patients at High Risk for Endarterectomy) trial suggests high risk patients have lower rates of death, heart attack and stroke after receiving a stent comparing those who have an endarterectomy. AUDIENCE INQUIRY For general information on carotid artery disease and treatments: American Heart Association, http://www.americanheart.org, or contact your local chapter National Institute of Neurological Disorders and Stroke, http://www.ninds.nih.gov Society for Vascular Surgery, VascularWeb, http://www.vascularweb.org BIBLIOGRAPHY Bush, Ruth, M.D., et al., "A Comparison of Carotid Artery Stenting with Neuroprotection Versus Carotid Endarterectomy Under Local Anesthesia," The American Journal of Surgery, November 2005, Vol. 190, No. 5, pp. 696-700. "Carotid Artery Disease," Chicago: Society for Vascular Surgery, VascularWeb, downloaded from website (http://www.vascularweb.org), May 26, 2006. 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Press, Matthew, M.D., et al., "Predicting Medical and Surgical Complications of Carotid Endarterectomy," Archives of Internal Medicine, April 24, 2006, Vol. 166, No. 8, pp. 914-920. "Questions and Answers About Carotid Endarterectomy," Bethesda: National Institute of Neurological Disorders and Stroke, downloaded from website (http://www.ninds.nih.gov), May 26, 2006. Rajamani, Kumar, and Seeman, Chaturvedi, M.D., "Medical Management of Carotid Artery Disease," Seminars in Neurology, December 2005, Vol. 25, No. 4, pp. 376-383. Research compiled and edited by Barbara J. Fister