The carotid arteries are located in the neck and provide the brain with most of its blood supply. Carotid artery disease develops when these arteries become narrowed, or occluded, by an accumulation of a fatty substance called plaque. The build-up of plaque inside the walls of the artery is due to a process called atherosclerosis ("hardening of the arteries"), and the resulting narrowing is called "stenosis."
If plaque builds up to the point that it obstructs blood flow to the brain, or particles of the plaque break off and travel to arteries within the brain, a person can develop a stroke or a "mini" stroke (TIA). Stroke is caused by a stoppage of blood flow to any part of the brain for any reason, which leads to damage of that part of the brain, and is an emergency condition requiring prompt treatment to prevent permanent brain injury.
Carotid artery disease causes more than a third of all strokes, which strike more than 750,000 people in the United States each year. Stroke is the third highest cause of death and the leading cause of disability in the United States.
In some patients with carotid artery disease, doctors may place a stent (a small mesh support tube) at the site of the blockage in the carotid artery. The procedure is performed under local anesthesia. The stent is inserted via a catheter placed into the femoral artery in the groin and threaded through the blood vessels of the body to the area of the blockage.
Once the catheter reaches the blockage, a protective filter is placed between the blockage and the brain to capture any particles that might be released by the procedure. The stent is then placed at the area of the blockage and deployed. After the stent is in place, the filter protection device is removed. The stent is left permanently in the artery to provide a reinforced channel through which blood can flow. Patients usually go home the following day.
Clinical trials are seeking to determine if patients with blockages in large arteries fare better if endovascular techniques – which employ devices inserted into the blocked artery through a catheter – are used. The catheter is inserted into the femoral artery in the groin and threaded up to the blocked artery in the brain, where the device is deployed. The newest devices are "stent retrievers." With one such approach, a self-expanding stent-like device connected to a wire; the stent opens, the clots adheres to it, and the stent can be pulled out, taking the clot with it.