The carotid arteries are the main blood vessels on each side of the neck that carry blood to the head. Like the arteries in the heart, the carotid arteries can also be affected by plaque building up in and slowing the flow of blood to the brain. The condition can have serious consequences in one of two ways. First, the plaque can build to create a serious clog. This blockage is referred to as “stenosis.” Second, blood clots or pieces of the plaque can break off and become lodged further up the artery, blocking blood flow. In either case, the area of the brain fed by that artery is deprived of oxygenated blood, causing a stroke, or death of the affected brain cells.
Patients with mild to moderate degrees of carotid stenosis can sometimes be treated with lifestyle changes, diet modification, weight loss, increased physical activity and medications. For more serious blockages, doctors may recommend a surgical procedure called a carotid endarterectomy. An incision is made into the neck on the side of the blockage. A clamp is temporarily placed on the vessel to stop blood from flowing through it. In some cases, doctors may attach a tube above and below the blockage to allow blood to flow around the plaque and continue to provide oxygen to the brain. Next, a cut is made into the side of the artery and the plaque is scraped away. The vessel is closed and the clamps or bypass tube are removed. Lastly, the neck incision is sutured.
Another procedure to open blocked carotid arteries is carotid stenting. It’s similar to the stenting procedure used to open blocked arteries in the heart. A balloon-tipped catheter is fed through the circulatory system up to the point of blockage in the carotid artery. As the balloon expands, it pushes the plaque against the wall of the artery, opening up the space for blood flow. As the balloon expands, it also opens a flexible metal device, called a stent. The stent remains open after the balloon is deflated, supporting the walls like a scaffold and keeping the plaque compressed.
Doctors at Memorial Hermann Heart and Vascular Institute/University of Texas Medical School are using a carotid stent, called the PRECISE® Nitinol Stent. The stent is used with another component, the ANGIOGUARD™ Emboli Capture Guidewire.
Prior to the placement of the balloon, the ANGIOGUARD is fed through the vessel to a point just beyond the blockage. Once in place, the ANGIOGUARD opens like an umbrella to catch bits of plaque or debris that may break off during angioplasty. Without the “filter” this debris could travel up the carotid artery and become lodged in a narrow artery in the brain, causing a stroke. The balloon is then inflated and the stent is deployed. Last, the ANGIOGUARD is closed and pulled out, carrying any debris it may have captured. Interventional
Cardiologist Richard Smalling, M.D., says the stent system is safe for use, even for high-risk patients, like those with lung disease and heart problems. It’s also a safe option for those who have carotid artery scarring from radiation therapy to the neck or prior carotid artery surgery.