Carotid Stenting treats the diseased, narrowed segment of the internal carotid artery in the neck.
The irregular surface of the vessel is predisposed to develop clots on it which can flick off or embolise to the head blocking the small arteries in the brain, causing a stroke.
The stent reopens the flow channel thus allowing smoother flow, as well as remodelling the artery by lining it with a protective metal scaffold. Stents have been in many arteries of the body for example the heart, the legs and this represents an extension of this technology into a new vessel. International experience with stenting is now out to 8 years with my personal experience over 4 years. It is an alternative to carotid surgery and is used selectively depending on the individual patient needs.
It has advantages in particular settings; for example in people with significant other medical illness where general anaesthesia is not desirable. It is also safer in those with dense scar tissue around the carotid artery, those who have had radiotherapy to the neck or have tracheostomy tubes.
It requires the anatomy of the vessels to be sympathetic to the procedure i.e. the arteries not being to tortuous or stiff. The procedure is done awake in a Catheter Lab with continuous monitoring of the blood pressure. Generally access to the circulation is obtained via the femoral artery in the groin. A long tube or sheath is placed into the root of the neck. Though this, a cerebral protection device is placed above the diseased segment to filter the blood of any clots that may dislodge during the procedure. This is removed at the end of the case. The narrowed vessel has the stent placed and then the stent and the artery are dilated up. At this point there may be some transient discomfort in the neck. At the end of the operation the access site in the artery is closed with a plug called an angioseal to prevent bleeding.
Patients are monitored in the Intensive Care Unit Post Operatively overnight and go home in the morning. The evidence available is that in most circumstances the results are similar to Open Carotid Surgery. The advantages to it are avoidance of a general anaesthetic, no surgical incision in the neck, no risk of damage to nearby structures i.e. nerves in the neck. The down side is that we don’t have long term data on outcomes beyond ten years, it is only suitable to those with appropriate anatomy and while the risk of some complications i.e. heart attack is lower the stroke risk may be slightly higher.