Carotid Artery Stenting (CAS)

The Carotid artery supplied blood to the brain. There are two carotid arteries and two vertebral arteries that together supply the whole of the brain with blood. Narrowing of the internal carotid artery is associated with a risk of stroke in well people. Two studies have suggested that treating these narrowings reduces the risk of stroke compared to tablets alone.

After a stroke or a mini-stroke, if a narrowing in the carotid artery is found (as in 5% of cases), then treatment is urgently needed and the benefits of removing the narrowing are much larger that in those who have not had a stroke.

There are two treatments available to treat the narrowing: Carotid Endarterectomy (CEA) and Carotid Artery Stenting (CAS). Careful consideration needs to be made on the choice of treatment and this will often involve neck scans, brain imaging and review with a multi-skilled team including neurologists, radiologist and vascular surgeons as well as the cardiologist. Whilst CAS is less invasive, avoids a general anaesthetic and avoids a neck incision, the CEA is better validated and may offer a smaller risk of stroke during the procedure. For a small number of patients either one or the other is the only choice. For the majority, the choice between CAS and CEA will be made by the patient and doctor together.

Carotid artery stenting involves a similar procedure to Coronary Angioplasty (PCI), with the insertion of a plastic pipe from the groin up to the neck. The danger from CAS is that the brain is unprotected from debris going upwards. Therefore, CAS is now usually done with a protection device in place (see below). This may be a balloon or filter to catch the debris.

Methods to protect the brain during carotid artery stenting.

Once the filter is in place, the angioplasty procedure is similar to the coronary angioplasty (see coronary angioplasty), except that a much larger stent is used. (see below). This stent scaffolds the debris behind its struts. The filter device is then removed and the plastic pipe removed from the leg artery. A plug is usually placed in the leg to speed up recovery. You normally stay overnight in hospital and need to continue of aspirn and clopidogrel for 1 month.

What are the risks from carotid artery stenting

The risk of bleeding from the leg is about 1%. The risk of stroke is 1-2%. Death is very rare. This has to be balanced with the risk of medical therapy- extremely high if a recent stroke has occurred before the internal carotid artery narrowing was found. A very rare complication that can occur after both carotid artery stent (CAS) and carotid endarterectomy (CEA) is bleeding into the brain. This is a serious problem, but good blood pressure control reduces the risk of this occurring.

Carotid artery angiogram before treatment of the internal carotid artery stenosis (left sided picture) and after the stent (middle picture). For comparison an open operation is shown as they are about to close up the wound. The dots are the stitches on the repaired artery.(right picture)