• Clinical science

Carotid artery stenosis

Abstract

Carotid artery stenosis (CAS) is an atherosclerotic, degenerative disease of the common carotid artery and internal carotid artery. Risk factors include advanced age, tobacco use, arterial hypertension, and diabetes mellitus. Depending on the extent of stenosis, ischemia in the carotid perfusion territory can result in amaurosis fugax, TIA, or stroke, and a bruit may be auscultated over the stenosis. Carotid duplex ultrasonography is the initial test of choice for evaluating asymptomatic patients. All symptomatic patients should undergo noncontrast CT or MRI to rule out acute or previous cerebral ischemia. Management depends on symptoms and the degree of stenosis. Lifestyle modifications and antiplatelet, antihypertensive, and statin therapy are recommended for all patients. Carotid endarterectomy is recommended for symptomatic patients with a stenosis ≥ 70% and asymptomatic patients with a stenosis ≥ 80%, but may also be considered in highly selected patients with moderate stenosis. Alternatively, if surgery is not feasible, carotid artery stenting may be performed.

Etiology

Clinical features

Carotid artery stenosis does not typically cause vertigo, lightheadedness, or syncope.

References:[1]

Diagnostics

  • First test: carotid duplex ultrasonography (may not detect mild stenosis)
    • Findings: focally increased velocity of blood flow
  • MRA or CTA: indicated for asymptomatic patients with inconclusive ultrasound
  • Noncontrast CT or MRI: indicated for all symptomatic patients (see stroke imaging for details)
  • Digital subtraction angiography (DSA)

References:[2][3]

Treatment

  • Medical management: recommended for all patients
  • Carotid endarterectomy (CEA): recanalization of the carotid artery
    • Indications
      • Symptomatic patients
        • Carotid artery stenosis ≥ 70%
        • Moderate carotid artery stenosis (50%–69%): depends on patient's age, sex, and comorbidities
      • Asymptomatic patients
        • Carotid artery stenosis ≥ 80%
        • Moderate carotid artery stenosis (60%–79%): depends on patient's age, sex, and comorbidities
    • Contraindications:
      • Life expectancy of < 5 years
      • Symptomatic carotid artery stenosis < 50%
      • Asymptomatic complete carotid occlusion
      • Prior ipsilateral endarterectomy
      • Perioperative risk of a stroke/death: ≥ 6% in symptomatic patients; ≥ 3% in asymptomatic patients
      • History of prior neck surgery/irradiation
  • Carotid artery stenting (CAS): angioplasty and stenting as an alternative to CEA
    • Can be considered if surgery is not feasible (e.g., poor surgical access to the stenosis, comorbidities that increase perioperative mortality)
    • Increased risk of periprocedural complications compared to CEA

References:[4][5][3][6][7]

Complications

  • Stroke
    • Asymptomatic carotid artery stenosis: annual risk of stroke is 0.5–1% (stenosis > 50%)
  • Carotid artery stenosis is considered an indicator for increased risk of myocardial infarction and cardiovascular death.
  • Complications of CEA (during and after the procedure)

References:[5]

We list the most important complications. The selection is not exhaustive.

Prevention

  • Screening for asymptomatic carotid artery stenosis is only recommended in patients with a high risk of stroke (e.g., age > 65 years, coronary artery disease, dyslipidemia, history of tobacco use)
  • Noninvasive methods (e.g., duplex ultrasonography, MRA)

References:[5][1]