Carotid Stenting

Authors: Dr Peter Mitchell*
                            Dr Winston Chong *

What are the generally accepted indications for carotid stenting?

Carotid stenting is one of two potential procedures for management of a transient ischaemic attack or stroke associated with a carotid stenosis of >70%. The alternative is carotid endarterectomy.

The procedure is indicated where there are relative contraindications to carotid endarterectomy (see below) or patient preference for carotid angioplasty and stent.

What are the prerequisites for having a carotid stenting done?

1. Clinical criteria (related to the above section). The patient needs to be reviewed by a neurologist or other person experienced in assessing neurological symptoms and neurovascular disease in particular.
2. Pre-procedure:
   1. Pre-procedural imaging. This would usually be CT angiography or catheter angiography. Generally, carotid duplex Doppler would not be considered adequate as the sole preoperative imaging test to demonstrate the degree of vessel narrowing.
   2. Baseline pathology. It is also important to test the baseline kidney function, clotting profile, Full Blood Examination (FBE).

What are the absolute contraindications for a carotid stenting?

The absolute contraindications for carotid stenting are coagulopathy that cannot be corrected or an inability to take antiplatelet medications (e.g. allergies to Aspirin or Clopidogrel).
Also see InsideRadiology ‘Angiography’ for further possible procedural contraindications.

What are the relative contraindications for a carotid stenting?

Relative contraindications for carotid stenting include renal impairment, contrast allergy and marked vessel tortuosity (particularly elongation of the aortic arch).

What are the adverse effects of carotid stenting?

1) Early.

Local:

There might be some discomfort in the region of the stent for a period of days to weeks, but this usually improves by itself. Other risks include haematoma or pseudoaneurysm at the groin puncture site, or, more seriously, dissection of the femoral or carotid artery.

Contrast can be damaging to kidneys, particularly in people who already have poorly functioning kidneys. Occasionally, people can be allergic to the contrast material (See Iodine-containing contrast medium (ICCM)).

Systemic:

Stroke occurs in between 2% and 10% of carotid stenting procedures carried out. This risk is highest during the procedure, and soon after (e.g. days), but greatly reduces to a very small risk weeks/months later due to in-stent thrombosis.

2) Late.

Restenosis occurs in 6% of patients within 2 years. Checking for this is the reason for the follow-up imaging. If this occurs, the re-narrowed area can be restretched with a balloon.
Also see InsideRadiology ‘Angiography’ for further information.

Is there any specific post procedural care required after carotid stenting?

The patient will need to have an imaging procedure (usually CT angiography) 3–6 months after the procedure.

Angiography suites have exacting protocols designed to limit the possibility of bleeding complications after angiography. These include instructions to patients regarding periods where they must lie flat, when they can sit up, gently mobilise and so on. On occasion, a patient will develop a delayed groin haematoma or bleed having left the angiography suite. The treatment involves lying the patient flat, applying compression to the puncture site and communicating with the angiography suite or on-call emergency (radiology) service. Occasionally, hospital admission to limit the bleeding and to correct any associated hypotension, blood loss and so on might be required.

Referrers should observe for worsening symptoms post-angiography; for example, delayed or new neurological symptoms. If that occurs, contact the emergency department of local hospital and, if possible, contact the radiologist who carried out the angiogram. Emergency reintervention might be required.

Delayed-onset rash can occur usually within 24 hours of the procedure. It is usually self-limiting, and requires symptomatic treatment only.

Are there alternative imaging tests, interventions or surgical procedures to a carotid stenting?

The purpose of carotid stenting or surgical endarterectomy is to reduce the chance of stroke. Both procedures are considered more effective than medical therapy in patients with a greater than 70% stenosis.

Although the complication rate of stenting is similar to carotid endarterectomy, it is not yet proven which procedure is safer.

Currently, it is believed that people considering carotid stenting should be experiencing symptoms from a narrowed artery and be considered as having a higher than average risk when considering possible surgery.

Carotid stenting and surgery can both cause stroke. Sometimes surgery can also cause damage to the recurrent laryngeal nerves. This is not a problem of carotid stenting. The recovery period from an uncomplicated procedure in carotid stenting would normally be quicker than a similarly uncomplicated procedure for carotid endarterectomy.

*The author has no conflict of interest with this topic.

Page last modified on 26/7/2017.