Carotid Stenosis: Carotid Endarterectomy (CEA)
Carotid artery atherosclerosis begins to form at 20 years of age. Plaques tend to grow on the back wall of the common carotid artery (CCA) and then encroach on the lumen of the Internal Carotid Artery (ICA) as they enlarge with time. Carotid artery stenosis may be asymptomatic or symptomatic.
Asymptomatic carotid stenosis is relatively prevalent in the general population, especially the elderly, with rates of 2.3% in ages 45-54 years and 8.2% at 75 years and over. It is differentiated from symptomatic carotid stenosis based on non-specific visual complaints, dizziness, or syncope not associated with Transient Ischemic Attack (TIA) or stroke. Asymptomatic carotid stenosis has low risk for ipsilateral cerebral infarction, with a stroke rate of 2% per year. It is usually discovered as a carotid bruit.
Symptomatic carotid stenosis may present as TIA, Reversible I... Neurological Deficit (RIND), or Cerebrovascular Accident (CVA), retinal insufficiency or infarction due to involvement of the central retinal artery.
Carotid stenosis may be managed medically or surgically. Medical management includes antiplatelet therapy and optimization of blood pressure, anti-cholesterol and diabetes therapy. Patients with low surgical risk, life expectancy > 5 years, and carotid stenosis > 60% see the most benefit from CEA in the asymptomatic group.
The North American Symptomatic Carotid Endarterectomy Trial (NASCET) has shown 17% reduction of CVA and 7% reduction of mortality at 18 months’ follow-up, in patients with high-grade carotid stenosis (>70%) and ipsilateral hemispheric or retinal TIA or CVA who undergo Surgery (Carotid Endarterectomy, CEA) within 120 days of the event vs. medical management. Results are twice as good with stenosis 90-99%.
Briefly, surgical approach involves initial dissection in the neck through a small incision, with care taken to spare the ansa hypoglossi and hypoglossal nerve; temporary occlusion of the involved vessels in this order: ICA, CCA and ECA (This procedure is called “ICE), opening of the involved vessel (arteriotomy), plaque removal, leaving as smooth an edge as possible; arteriotomy closure, either primary closure or with a patch graft; and vessel release, ECA first, CCA next and ICA last, (‘de-ICE’) in order to minimize risk of small pieces of the plaque reaching the brain and cause stroke.
The most common postoperative complication of CEA is cranial nerve injury, with an incidence of 8-10%. Others include stroke (5%), post-op TIA (generally due to ICA occlusion), seizures (most occurring post-op day 5-13), cerebral hypo perfusion syndrome, hoarseness (most commonly due to laryngeal edema and not laryngeal nerve injury), headache, and hypertension. Disruption of arteriotomy closure is rare but emergent. In-hospital mortality rate is 1%.