====== Common Carotid Artery Stenosis ======

{{rss>https://pubmed.ncbi.nlm.nih.gov/rss/search/1h7Su3P88Y-m0JJQ2SQcHTXmDe6lONoJyZJPWjYK3GFP_1xgvj/?limit=15&utm_campaign=pubmed-2&fc=20250702201722}}

Common carotid artery stenosis (CCAS) refers to the narrowing of the common carotid artery (CCA), usually due to atherosclerosis. It can impair cerebral perfusion and increase the risk of ischemic stroke, particularly via embolization to the internal carotid artery or cerebral vessels.

===== Classification of Common Carotid Artery Stenosis =====

Classification of stenosis is typically based on the percentage of luminal narrowing, often estimated by duplex ultrasound or angiographic imaging. While most guidelines focus on internal carotid stenosis, the same grading principles are applied to the common carotid artery.

^ Degree of Stenosis ^ Luminal Narrowing ^ Hemodynamic Impact ^ Clinical Relevance ^
| **Normal**          | < 20%             | None                | Physiologic |
| **[[Mild Common Carotid Artery Stenosis]]**            | 20–49%            | Minimal             | Often asymptomatic |
| **Moderate**        | 50–69%            | Flow turbulence     | May be symptomatic |
| **Severe**          | 70–99%            | Critically reduced flow | High risk of stroke |
| **Occlusion**       | 100%              | No flow             | Established collateral circulation or acute ischemia |

===== Measurement Criteria =====
  * **Duplex Ultrasound**: Peak systolic and end-diastolic velocities compared to internal carotid artery.
  * **CT/MR Angiography**: Percentage of narrowing calculated using the NASCET or ECST methods adapted for CCA.
  * **DSA (Digital Subtraction Angiography)**: Gold standard, used for surgical planning.

===== Important Notes =====
  * Unlike internal carotid stenosis, common carotid stenosis rarely causes symptoms directly unless it affects downstream flow.
  * Classification guides decision-making in conjunction with symptoms and comorbidities.

===== Etiology =====
  * Atherosclerosis (most common)
  * Fibromuscular dysplasia
  * Radiation-induced vasculopathy
  * Arteritis (e.g., Takayasu, giant cell)
  * Carotid artery dissection
  * Post-traumatic or post-surgical changes

===== Clinical Presentation =====
  * Often asymptomatic
  * Transient ischemic attacks (TIAs)
  * Amaurosis fugax
  * Stroke
  * Carotid bruit on physical examination

===== Diagnosis =====
  * **Carotid Duplex Ultrasound** – first-line screening
  * **CT Angiography (CTA)** or **MR Angiography (MRA)** – detailed evaluation
  * **Digital Subtraction Angiography (DSA)** – gold standard, used selectively

===== Severity Classification =====
  * Mild: < 50% stenosis
  * Moderate: 50–69%
  * Severe: ≥ 70%

===== Treatment =====

==== Medical Management ====
  * Antiplatelet therapy (aspirin or clopidogrel)
  * Statin therapy
  * Blood pressure control
  * Diabetes management
  * Smoking cessation

==== Revascularization ====
  * **Carotid Endarterectomy (CEA)**:
    * Symptomatic patients with ≥70% stenosis
    * Consider in 50–69% if symptomatic and low surgical risk
  * **Carotid Artery Stenting (CAS)**:
    * For patients at high surgical risk

===== Prognosis =====
  * Stroke risk correlates with degree of stenosis and symptomatology
  * Optimized medical therapy significantly reduces long-term risk

===== See Also =====
  * [[internal carotid artery stenosis]]
  * [[carotid artery dissection]]
  * [[subclavian steal syndrome]]