Percutaneous transarterial carotid artery stent placement for asymptomatic extracranial carotid stenosis

The main arteries in the neck (the carotid arteries) can become narrowed by fatty deposits (extracranial carotid stenosis). Blood clots can form on these fatty deposits. Fragments can then detach, and lodge in thinner arteries that supply blood to parts of the brain. This can cause a stroke or a transient ischaemic attack (sometimes called a 'mini stroke'). In some people, the carotid stenosis is asymptomatic. It may be identified incidentally during imaging and investigations for other conditions, or during health screening.

For people with asymptomatic extracranial carotid stenosis, management includes lifestyle modification (diet, exercise and smoking cessation) and pharmacological therapy (antithrombotics, lipid-lowering agents, blood pressure reduction and glycaemic control). Some people with severe stenosis may be offered revascularisation and the conventional surgical approach used is carotid endarterectomy (CEA). This involves making an incision in the side of the neck to access the narrowed section of artery to remove the fatty deposits. A newer alternative approach is transcervical carotid artery revascularisation, which uses a transcarotid neuroprotection system. The common carotid artery is accessed directly, through a smaller incision than in CEA. This procedure is not being considered in this guidance. NICE's interventional procedures guidance on transcervical extracorporeal reverse flow neuroprotection for reducing the risk of stroke during carotid artery stenting was published in 2016.

Carotid artery stent placement is usually done under local anaesthetic, after imaging. It involves passing a guidewire into the carotid artery. The usual access point is the common femoral artery, but radial access has also been used. The carotid stenosis is then usually predilated using a balloon catheter. A metal mesh (stent) is inserted, which keeps the artery open to maintain blood flow and prevent restenosis and embolism.

Embolic protection devices are often used during the procedure to reduce the risk of procedural cerebral emboli.

Carotid stenting is a less invasive percutaneous alternative to CEA. Potential advantages include the avoidance of general anaesthesia and the need for a neck incision that may result in cranial and cutaneous nerve damage. The rate of general surgical complications such as myocardial infarction may also be reduced.